feat(库):通过Gradle添加ActiveAndroid库
feat(Application):添加MyApplication类
feat(初始化):通过MyApplication类初始化ActiveAndroid
feat(model):创建Item，Category两个Model
feat(activeandroid):save 进行中
feat(activeandroid):save 进行中
feat(activeandroid):Active-Android Demo完成
Merge branch 'demo-activeandroid' of github.com:Morphin3/JourneyToAndroid into demo-activeandroid

Conflicts:
	JourneyToAndroid/journeytoandroid/src/main/java/com/taoism/journeytoandroid/activeandroid/ActiveAndroidDemo.java
	JourneyToAndroid/journeytoandroid/src/main/java/com/taoism/journeytoandroid/activeandroid/model/Category.java
	JourneyToAndroid/journeytoandroid/src/main/java/com/taoism/journeytoandroid/activeandroid/model/Item.java
	JourneyToAndroid/journeytoandroid/src/main/res/layout/demo_activeandroid.xml
Merge branch 'demo-activeandroid' into develop