refactor builder;
Merge branch 'master' of
https://github.com/androidzhaoxiaogang/rocket.git

Conflicts:
	src/fast/rocket/builder/BitmapBuilder.java
	src/fast/rocket/builder/LoadBuilder.java
	src/fast/rocket/builder/RequestBuilder.java
	src/fast/rocket/builder/RocketImageBuilder.java
	src/fast/rocket/builder/RocketJsonBuilder.java
	src/fast/rocket/cache/ImageLoader.java
	src/fast/rocket/utils/ImageUtils.java