🏗 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/fan/__init__.py

@@ -0,0 +1,25 @@
+import esphome.codegen as cg
+import esphome.config_validation as cv
+from esphome.components import fan, output
+from esphome.const import CONF_OSCILLATION_OUTPUT, CONF_OUTPUT, \
+    CONF_OUTPUT_ID
+from .. import binary_ns
+
+BinaryFan = binary_ns.class_('BinaryFan', cg.Component)
+
+CONFIG_SCHEMA = cv.nameable(fan.FAN_SCHEMA.extend({
+    cv.GenerateID(CONF_OUTPUT_ID): cv.declare_variable_id(BinaryFan),
+    cv.Required(CONF_OUTPUT): cv.use_variable_id(output.BinaryOutput),
+    cv.Optional(CONF_OSCILLATION_OUTPUT): cv.use_variable_id(output.BinaryOutput),
+}).extend(cv.COMPONENT_SCHEMA))
+
+
+def to_code(config):
+    output_ = yield cg.get_variable(config[CONF_OUTPUT])
+    state = yield fan.create_fan_state(config)
+    var = cg.new_Pvariable(config[CONF_OUTPUT_ID], state, output_)
+    yield cg.register_component(var, config)
+
+    if CONF_OSCILLATION_OUTPUT in config:
+        oscillation_output = yield cg.get_variable(config[CONF_OSCILLATION_OUTPUT])
+        cg.add(var.set_oscillation(oscillation_output))