Remove header files of TouchVG which can be automatically compiled.
Update README.
Merge branch 'master' into ColorPad.
Merge pull request #2 from ljlin/ColorPad

参考ColorPad使用Storyboard实现UI
Merge branch 'ljlin/ColorPad' into ColorPad.

忽略touchvg的头文件和bundle文件。
修正[ViewController viewDidLoad]中创建绘图视图的错误，这会导致按钮不可点中。