🏗 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/fastled_spi/light.py

@@ -0,0 +1,35 @@
+import esphome.codegen as cg
+import esphome.config_validation as cv
+from esphome import pins
+from esphome.components import fastled_base
+from esphome.const import CONF_CHIPSET, CONF_CLOCK_PIN, CONF_DATA_PIN, CONF_NUM_LEDS, CONF_RGB_ORDER
+
+AUTO_LOAD = ['fastled_base']
+
+CHIPSETS = [
+    'LPD8806',
+    'WS2801',
+    'WS2803',
+    'SM16716',
+    'P9813',
+    'APA102',
+    'SK9822',
+    'DOTSTAR',
+]
+
+CONFIG_SCHEMA = cv.nameable(fastled_base.BASE_SCHEMA.extend({
+    cv.Required(CONF_CHIPSET): cv.one_of(*CHIPSETS, upper=True),
+    cv.Required(CONF_DATA_PIN): pins.output_pin,
+    cv.Required(CONF_CLOCK_PIN): pins.output_pin,
+}))
+
+
+def to_code(config):
+    var = yield fastled_base.new_fastled_light(config)
+
+    rgb_order = None
+    if CONF_RGB_ORDER in config:
+        rgb_order = cg.RawExpression(config[CONF_RGB_ORDER])
+    template_args = cg.TemplateArguments(cg.RawExpression(config[CONF_CHIPSET]),
+                                         config[CONF_DATA_PIN], config[CONF_CLOCK_PIN], rgb_order)
+    cg.add(var.add_leds(template_args, config[CONF_NUM_LEDS]))