Add gradlew and updated com.android.tools.build:gradle to 0.13.0
Fix #191 and fix #193
Merge remote-tracking branch 'origin/master'
Pull API interface out. Add isShowing() method
Remove GlobalLayout inheritance
Remove more inheritance
Merge pull request #230 from kamiox/master

Added gradlew and updated com.android.tools.build:gradle to 0.13.0
Update Readme for new features
Add min SDK comment