Update Gradle wrapper to Gradle 1.10

Also add a Gradle task for updating the wrapper

Signed-off-by: Eddie Ringle <eddie@eringle.net>
Update Android Gradle plugin to 0.8.+

Signed-off-by: Eddie Ringle <eddie@eringle.net>
Set buildToolsVersion to 19.0.1

* For compatibility with Gradle 1.10

Signed-off-by: Eddie Ringle <eddie@eringle.net>