🏗 Merge C++ into python codebase (#504)

## Description:

Move esphome-core codebase into esphome (and a bunch of other refactors). See https://github.com/esphome/feature-requests/issues/97

Yes this is a shit ton of work and no there's no way to automate it :( But it will be worth it 👍

Progress:
- Core support (file copy etc): 80%
- Base Abstractions (light, switch): ~50%
- Integrations: ~10%
- Working? Yes, (but only with ported components).

Other refactors:
- Moves all codegen related stuff into a single class: `esphome.codegen` (imported as `cg`)
- Rework coroutine syntax
- Move from `component/platform.py` to `domain/component.py` structure as with HA
- Move all defaults out of C++ and into config validation.
- Remove `make_...` helpers from Application class. Reason: Merge conflicts with every single new integration.
- Pointer Variables are stored globally instead of locally in setup(). Reason: stack size limit.

Future work:
- Rework const.py - Move all `CONF_...` into a conf class (usage `conf.UPDATE_INTERVAL` vs `CONF_UPDATE_INTERVAL`). Reason: Less convoluted import block
- Enable loading from `custom_components` folder.

**Related issue (if applicable):** https://github.com/esphome/feature-requests/issues/97

**Pull request in [esphome-docs](https://github.com/esphome/esphome-docs) with documentation (if applicable):** esphome/esphome-docs#<esphome-docs PR number goes here>

## Checklist:
  - [ ] The code change is tested and works locally.
  - [ ] Tests have been added to verify that the new code works (under `tests/` folder).

If user exposed functionality or configuration variables are added/changed:
  - [ ] Documentation added/updated in [esphomedocs](https://github.com/OttoWinter/esphomedocs).

esphome/components/binary_sensor/automation.h

@@ -0,0 +1,161 @@
+#pragma once
+
+#include "esphome/core/component.h"
+#include "esphome/core/automation.h"
+#include "esphome/components/binary_sensor/binary_sensor.h"
+
+namespace esphome {
+namespace binary_sensor {
+
+struct MultiClickTriggerEvent {
+  bool state;
+  uint32_t min_length;
+  uint32_t max_length;
+};
+
+class PressTrigger : public Trigger<> {
+ public:
+  explicit PressTrigger(BinarySensor *parent) {
+    parent->add_on_state_callback([this](bool state) {
+      if (state)
+        this->trigger();
+    });
+  }
+};
+
+class ReleaseTrigger : public Trigger<> {
+ public:
+  explicit ReleaseTrigger(BinarySensor *parent) {
+    parent->add_on_state_callback([this](bool state) {
+      if (!state)
+        this->trigger();
+    });
+  }
+};
+
+bool match_interval(uint32_t min_length, uint32_t max_length, uint32_t length);
+
+class ClickTrigger : public Trigger<> {
+ public:
+  explicit ClickTrigger(BinarySensor *parent, uint32_t min_length, uint32_t max_length)
+      : min_length_(min_length), max_length_(max_length) {
+    parent->add_on_state_callback([this](bool state) {
+      if (state) {
+        this->start_time_ = millis();
+      } else {
+        const uint32_t length = millis() - this->start_time_;
+        if (match_interval(this->min_length_, this->max_length_, length))
+          this->trigger();
+      }
+    });
+  }
+
+ protected:
+  uint32_t start_time_{0};  /// The millis() time when the click started.
+  uint32_t min_length_;     /// Minimum length of click. 0 means no minimum.
+  uint32_t max_length_;     /// Maximum length of click. 0 means no maximum.
+};
+
+class DoubleClickTrigger : public Trigger<> {
+ public:
+  explicit DoubleClickTrigger(BinarySensor *parent, uint32_t min_length, uint32_t max_length)
+      : min_length_(min_length), max_length_(max_length) {
+    parent->add_on_state_callback([this](bool state) {
+      const uint32_t now = millis();
+
+      if (state && this->start_time_ != 0 && this->end_time_ != 0) {
+        if (match_interval(this->min_length_, this->max_length_, this->end_time_ - this->start_time_) &&
+            match_interval(this->min_length_, this->max_length_, now - this->end_time_)) {
+          this->trigger();
+          this->start_time_ = 0;
+          this->end_time_ = 0;
+          return;
+        }
+      }
+
+      this->start_time_ = this->end_time_;
+      this->end_time_ = now;
+    });
+  }
+
+ protected:
+  uint32_t start_time_{0};
+  uint32_t end_time_{0};
+  uint32_t min_length_;  /// Minimum length of click. 0 means no minimum.
+  uint32_t max_length_;  /// Maximum length of click. 0 means no maximum.
+};
+
+class MultiClickTrigger : public Trigger<>, public Component {
+ public:
+  explicit MultiClickTrigger(BinarySensor *parent, const std::vector<MultiClickTriggerEvent> &timing)
+      : parent_(parent), timing_(timing) {}
+
+  void setup() override {
+    this->last_state_ = this->parent_->state;
+    auto f = std::bind(&MultiClickTrigger::on_state_, this, std::placeholders::_1);
+    this->parent_->add_on_state_callback(f);
+  }
+
+  float get_setup_priority() const override { return setup_priority::HARDWARE; }
+
+  void set_invalid_cooldown(uint32_t invalid_cooldown) { this->invalid_cooldown_ = invalid_cooldown; }
+
+ protected:
+  void on_state_(bool state);
+  void schedule_cooldown_();
+  void schedule_is_valid_(uint32_t min_length);
+  void schedule_is_not_valid_(uint32_t max_length);
+  void trigger_();
+
+  BinarySensor *parent_;
+  std::vector<MultiClickTriggerEvent> timing_;
+  uint32_t invalid_cooldown_{1000};
+  optional<size_t> at_index_{};
+  bool last_state_{false};
+  bool is_in_cooldown_{false};
+  bool is_valid_{false};
+};
+
+class StateTrigger : public Trigger<bool> {
+ public:
+  explicit StateTrigger(BinarySensor *parent) {
+    parent->add_on_state_callback([this](bool state) { this->trigger(state); });
+  }
+};
+
+template<typename... Ts> class BinarySensorCondition : public Condition<Ts...> {
+ public:
+  BinarySensorCondition(BinarySensor *parent, bool state, uint32_t for_time = 0)
+      : parent_(parent), state_(state), for_time_(for_time) {
+    parent->add_on_state_callback([this](bool state) { this->last_state_time_ = millis(); });
+  }
+  bool check(Ts... x) override {
+    if (this->parent_->state != this->state_)
+      return false;
+
+    return millis() - this->last_state_time_ >= this->for_time_;
+  }
+
+ protected:
+  BinarySensor *parent_;
+  bool state_;
+  uint32_t last_state_time_{0};
+  uint32_t for_time_{0};
+};
+
+template<typename... Ts> class BinarySensorPublishAction : public Action<Ts...> {
+ public:
+  explicit BinarySensorPublishAction(BinarySensor *sensor) : sensor_(sensor) {}
+  TEMPLATABLE_VALUE(bool, state)
+  void play(Ts... x) override {
+    auto val = this->state_.value(x...);
+    this->sensor_->publish_state(val);
+    this->play_next(x...);
+  }
+
+ protected:
+  BinarySensor *sensor_;
+};
+
+}  // namespace binary_sensor
+}  // namespace esphome