* Added missing docs for Renderer options

* Fixed line order

* Fixed typos

* Fixes typos

* Documents events for DisplayObject, renderers, Texture and BaseTexture

* Converts to single-line event syntax

* Adds mouse/touch/pointer events for DisplayObject, fixes typo, adds interactive and interactiveChildren

* Added missing params on touchcancel and pointercancel

* Better helper docs for DisplayObject and Container

* Fix lint

* Removes mixin doc for PIXI.interaction.interactiveTarget

* Added more explicit types for `originalEvent`

* Fixes lint issue

* Better job documenting plugins and namespace

* Fixes linting errors

* Disabling hardwrap because of ESlint

* @readOnly becomes @readonly

* Fixes description, adds link, more info about excluding plugins

* Missed description

* Fixes typos

* Adds missing word

* User can decide whether  auto-set the projection

`bindShader` always  set the projection matrix  automatically . in most case ,  that's OK.

But When I create some new renderer of PIXI ,  sometimes it would make some problems.
e.g.
* shader no projectionMatrix
* shader need use a custom projectionMatrix (not  _activeRenderTarget's)
* shader use a cached array (don't want to call toArray every time)

So I add a new argument to `bindShader` , and the default value is true, so  it would break any current code of PIXI

.

* Update WebGLRenderer.js

* Add a easy way to clear RenderTexture

In current PIXI, clear a RenderTexture is complex : 
```
renderer.bindRenderTexture(myRenderTexture);
renderer.clear();
// restore the previous renderTexture
renderer.bindRenderTexture();
```
And bind renderTexture is a high-cost operation . We shouldn't call it for cleaning render texture.

So I  add this method.

relatived : https://github.com/pixijs/pixi.js/issues/3595

* Add `return this`

* Added legacy option to webGL renderer

Setting ```legacy``` to true now forces VertexArrayObjects and
MultiTexture Batching to be disabled. We also store the variable on the
renderer just incase we want to use it to force settings in anything
else.

also added a test

* remove WebGLTests as they don't work on server

* Added extra param to Application

* Adds WebGL test for legacy

* Better check for WebGL in tests

* Update WebGLRenderer.js

```
    this._activeRenderTarget = null;
    this._activeTextureLocation = 999;
    this._activeTexture = null;
````
must before `this._indexContext()` , otherwise  the _activeRenderTarget & _activeTexture init in  _indexContext will back to `null`.

* Add a blank line for cosmetic.

Dev vao state cache

* minimal texture bounds pass 1

* cheeky opts

* tidy up code

* create empty textures

* added empty texture

* couple more tweaks

* fixed empty texture issue

* fixed tweaked so id's sit on glTexture

means it should work on multiple contexts

* tweaked unbound textures

* tidy up

* upped max textures to 4 for mobile!

also sending state to tiling sprite VAO

* removed _activeTetureLocation

* tweaked eslint

* make sure buffer is bound

* updates based on @englercj review points

- Added vertexCount back in as it still yields much faster results in
iOS
- Tidied old comments
- Replaced i++ with ++i

Looks like since we call loseContext() on `WebGLRenderer#destroy()` that
if you create another WebGLRenderer with the same canvas the browser will
recycle that lost context and return it.

This means when we try to use the context it is actually in a lost state.
This change tries to restore a lost context before we use it. It also adds
a debug assert at one location that will be invalid if the context is
invalid.

* some more es6 changes
- const instead of let if possible
- arrow functions
- string templates
- argument defaults

* object property shorthand

* some more es6 changes
- const instead of let if possible
- arrow functions
- string templates
- argument defaults

* Revert "Merge branch 'dev-es6-sb' of github.com:stbaer/pixi.js into dev-es6-sb"

This reverts commit 8d3af81, reversing
changes made to e8b9948.

* Revert "Merge branch 'dev-es6' into dev-es6-sb"

This reverts commit 3eeaf79, reversing
changes made to fb69536.

* Revert "Revert "Merge branch 'dev-es6-sb' of github.com:stbaer/pixi.js into dev-es6-sb""

This reverts commit c860228.

* fix RenderTexture, incomplete merge

* fix for text font properties

* reverted some changes

* checked out License, Readme and Contributinf from dev-es6

* editorconfig updated: 2 spaces for .eslintrc

* added eslint rule: spaces around fat arrow

* used eslint fix for consistent spaces around fat arrow

* don't allow scale.x or scale.y to be 0 in displayObject setTransform

* removed jshint comments (again)

* Migration to ES6 classes

* Migration to ES6 classes

* Migration to ES6 classes

* Migration to ES6 classes

* Using babelify to transpile ES6 code

* Adding babel-preset-es2015 in devDependencies

* Epic run through the docs

* Fixed merge issue

* PIXI.utils now outputs its documentation correctly

Added context validator