Merge pull request #3189 from gameofbombs/dev4 ...

Canvas stuff

Dev texture states cacheing (#3201) ...

* 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

BlendMode canvas fix

Fix crash of DropShadow filter (#3162)

fix #1841 by defaults system renderer resolution

use objects where we map render context ids

Restore lost context before using it; fixes #2958 ...

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.

Fix #2971; merges #3046

strange imports problem

updated some doc comments (#3038)

filter clamp was wrong

Merge pull request #3024 from englercj/export-default-cleanup ...

cleanup some export defaults

clean up to be specific

cleanup some export defaults

Huge refactor to match a new shiny eslint file.

fix canvas resolution; manually merge #2870

small jsdoc fix - added some missing (#3008)

Prefer const (#3002) ...

* added prefer-const rule to .eslintrc

* eslint const autofixes

* manual let to const changes; lint free;

* added brace style 'allman' to eslintrc

* brace style, comment fixes and default arg

* brace style fixes

* more brace styles

* Point default args

* Point brace styles

* Observable Point default args

* more brace styles

* jsdoc comment style

* brace style

* brace styles and small jsdoc fix

* brace styles

* removed unneeded eslint inline comment

* brace styles; lint free

small fixes in the documentation

filter pad fix

some more es6 changes (#2969) ...

* 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)

Fixes lint error

Merge remote-tracking branch 'origin/dev-es6' into dev-es6

Merged with 'dev' ...

# Conflicts:
#	src/core/Shader.js
#	src/core/graphics/Graphics.js
#	src/core/math/shapes/Rectangle.js
#	src/core/renderers/webgl/managers/FilterManager.js
#	src/core/sprites/webgl/generateMultiTextureShader.js

removed old jshint comments; replaced jshint in CONTRIBUTING.md with eslint

typo

fixed filter issue

fix filter offset issue

Replaces jshint with eslint, using babel in loose mode

Update imports and exports, getters and setters