🏗 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/ttp229_lsf/__init__.py

@@ -0,0 +1,22 @@
+import esphome.codegen as cg
+import esphome.config_validation as cv
+from esphome.components import i2c
+from esphome.const import CONF_ID
+
+DEPENDENCIES = ['i2c']
+AUTO_LOAD = ['binary_sensor']
+
+CONF_TTP229_ID = 'ttp229_id'
+ttp229_ns = cg.esphome_ns.namespace('ttp229')
+
+TTP229LSFComponent = ttp229_ns.class_('TTP229LSFComponent', cg.Component)
+
+CONFIG_SCHEMA = cv.Schema({
+    cv.GenerateID(): cv.declare_variable_id(TTP229LSFComponent),
+}).extend(cv.COMPONENT_SCHEMA).extend(i2c.i2c_device_schema(0x57))
+
+
+def to_code(config):
+    var = cg.new_Pvariable(config[CONF_ID])
+    yield cg.register_component(var, config)
+    yield i2c.register_i2c_device(var, config)

esphome/components/ttp229_lsf/binary_sensor.py

@@ -0,0 +1,21 @@
+from esphome.components import binary_sensor
+import esphome.config_validation as cv
+import esphome.codegen as cg
+from esphome.const import CONF_CHANNEL, CONF_NAME, CONF_ID
+from . import ttp229_ns, TTP229LSFComponent, CONF_TTP229_ID
+
+DEPENDENCIES = ['ttp229_lsf']
+TTP229Channel = ttp229_ns.class_('TTP229Channel', binary_sensor.BinarySensor)
+
+CONFIG_SCHEMA = cv.nameable(binary_sensor.BINARY_SENSOR_SCHEMA.extend({
+    cv.GenerateID(): cv.declare_variable_id(TTP229Channel),
+    cv.GenerateID(CONF_TTP229_ID): cv.use_variable_id(TTP229LSFComponent),
+    cv.Required(CONF_CHANNEL): cv.All(cv.Coerce(int), cv.Range(min=0, max=15))
+}))
+
+
+def to_code(config):
+    hub = yield cg.get_variable(config[CONF_TTP229_ID])
+    var = cg.new_Pvariable(config[CONF_ID], config[CONF_NAME], config[CONF_CHANNEL])
+    yield binary_sensor.register_binary_sensor(var, config)
+    cg.add(hub.register_channel(var))

esphome/components/ttp229_lsf/ttp229.cpp

@@ -0,0 +1,43 @@
+#include "ttp229.h"
+#include "esphome/core/log.h"
+
+namespace esphome {
+namespace ttp229 {
+
+static const char *TAG = "ttp229";
+
+void TTP229LSFComponent::setup() {
+  ESP_LOGCONFIG(TAG, "Setting up ttp229...");
+  if (!this->parent_->raw_request_from(this->address_, 2)) {
+    this->error_code_ = COMMUNICATION_FAILED;
+    this->mark_failed();
+    return;
+  }
+}
+void TTP229LSFComponent::dump_config() {
+  ESP_LOGCONFIG(TAG, "ttp229:");
+  LOG_I2C_DEVICE(this);
+  switch (this->error_code_) {
+    case COMMUNICATION_FAILED:
+      ESP_LOGE(TAG, "Communication with TTP229 failed!");
+      break;
+    case NONE:
+    default:
+      break;
+  }
+}
+void TTP229LSFComponent::loop() {
+  uint16_t touched = 0;
+  if (!this->parent_->raw_receive_16(this->address_, &touched, 1)) {
+    this->status_set_warning();
+    return;
+  }
+  this->status_clear_warning();
+  touched = reverse_bits_16(touched);
+  for (auto *channel : this->channels_) {
+    channel->process(touched);
+  }
+}
+
+}  // namespace ttp229
+}  // namespace esphome

esphome/components/ttp229_lsf/ttp229.h

@@ -0,0 +1,36 @@
+#pragma once
+
+#include "esphome/core/component.h"
+#include "esphome/components/binary_sensor/binary_sensor.h"
+#include "esphome/components/i2c/i2c.h"
+
+namespace esphome {
+namespace ttp229 {
+
+class TTP229Channel : public binary_sensor::BinarySensor {
+ public:
+  TTP229Channel(const std::string &name, int channel) : BinarySensor(name), channel_(channel) {}
+  void process(uint16_t data) { this->publish_state(data & (1 << this->channel_)); }
+
+ protected:
+  int channel_;
+};
+
+class TTP229LSFComponent : public Component, public i2c::I2CDevice {
+ public:
+  void register_channel(TTP229Channel *channel) { this->channels_.push_back(channel); }
+  void setup() override;
+  void dump_config() override;
+  float get_setup_priority() const override { return setup_priority::DATA; }
+  void loop() override;
+
+ protected:
+  std::vector<TTP229Channel *> channels_{};
+  enum ErrorCode {
+    NONE = 0,
+    COMMUNICATION_FAILED,
+  } error_code_{NONE};
+};
+
+}  // namespace ttp229
+}  // namespace esphome