Merge pull request #176 from damonkohler/upgrade_gradle

Upgrades Gradle Wrapper to version 1.8.
Moves most attributes from AndroidManifest.xml into build.gradle.
Changes android_honeycomb_mr2 API level to 15. Less than 0.1% of devices run level 13.
Renames android_gingerbread_mr1 to android_10.
Renames android_honeycomb_mr2 to android_15.
Changes all Android projects under android_core to support both Eclipse and Android Studio.
Renames Camera to XYOrthographicCamera.
Fixes camera control gestures that stopped working after Honeycomb.