* Move all helpers into src/helpers
* Move curve helpers to their own file
* DOM helpers moved to their own file
* Update migration docs
* Remove migration docs on new functions
* Convert axis options from arrays to objects
* Updated all chart type defaults
* Throw errors when axis type or position are not specified
* Avoid raising unnecessary errors when merging options into the default configs
* Fix additional tests
* Ensure scale defaults are set if type is not explicitly defined
* Another step
* Include `scale` as `firstIDs.r`
* update docs
* Update for buildOrUpdateScales
* Update migration guide
* Add test back
* Early data parsing + stacking by value
* Review comments
* review comments
* Remove reduntant parsing
* Couple CC warnings
* Optimize filterBetween
* More migration info
`controllers.*.js` and `core.datasetController.js` are now importable (no more function export), that's why there is so many changes mainly due to one indentation level removed. Split code for `bar/horizontalBar` and `doughnut/pie` in separate files, added a global controllers import (`src/controllers/index.js`) and add tests to check that all dataset controllers are correctly registered under `chart.controllers.{type}`.
The bar `backgroundColor`, `borderColor`, `borderWidth` and `borderSkipped` options are now scriptable (unit tests, docs and a basic sample). Also fix the gulp task that generates the documentation on Windows.
When `barThickness: undefined|null` (default), we compute an optimal sample size based on the smallest tick interval reduced to prevent any bar to overlap (bar equally sized). Also added support for a special `barThickness: 'flex'` value (previous default) that globally arranges bars side by side to prevent any gap when percentage options are 1 (variable bar sizes).
Add a new `offset` option to scales to add extra space at edges and remove the `includeOffset` argument from `getPixelForValue()` and `getPixelForTick()`. The bar controller now automatically calculates the bar width to avoid overlaps. When `offsetGridLines` is true, grid lines move to the left by one half of the tick interval, and labels don't move.
Internal ticks are now stored as objects in the PRIVATE this._ticks member and must not be accessed directly from outside this class. this.ticks is around for a long time and hasn't been marked as private, so we can't change its structure without unexpected breaking changes. If you need to access the scale ticks, use scale.getTicks() instead.
