Adds runtime for cocos2d-x v3.2

Copies v3.1
Supports cocos2d-x v3.2

- Changes `draw()` with the new v3.2 API: `bool transformUpdated` -> `uint32_t transformFlags`
- cocos2d-ified the API:
  - `const char*` -> `const std::string&`
  - constructors and destructors are `protected` (not `public`)
  - using `_` prefix for ivars
Updates README with v3.2 information
Docs.
Docs.
Docs.
Docs.
Calculate curves ahead of time.

More memory (15 versus 6 floats per key) but faster curve look ups.
Cocos2d-iphone v.3.1 support

PolygonBatch has been removed since Cocos2d-iphone has automatic
batching. CCDrawingPrimitives calls have been changed to CCDrawNode
calls and the rendering of triangles have been ported to CCRenderer.
Xcode projects have been updated with the necessary GLKit dependancy
Fixed curves.

I shan't be trusted with math.
Merge pull request #256 from ricardoquesada/cocos2dx_v32

Cocos2dx v32
Use lastTime for AttachmentTimeline.

closes #221
Merge pull request #257 from jvasti/master

Cocos2d-iphone v.3.1 support
Fixes for the cocos2d-x v3.2 API
Merge pull request #260 from ricardoquesada/cocos2dx_v32_api_fixes

Fixes for the cocos2d-x v3.2 API
Minor license update for clarity.
Sample works with the new v3.2 API

Updates API in samples

Adds iOS and Mac projects. Convient Xcode project to test
the sample really easy.
Fixes compilation warnings
Merge pull request #261 from ricardoquesada/cocos2dx_v32_samples_fixes

Sample works with the new v3.2 API
[Bugfix]
http://esotericsoftware.com/forum/viewtopic.php?f=7&t=3244
Handle DefaultSkin being null