Update .idea settings
build maven and zip distribution

Build -source.jar and -javadoc.jar

Downgrade Android Gradle plugin to 0.5.4 to allow referencing android tasks
from publishing plugin. This does not work in 0.5.5.

Downgrade Gradle version to 1.6 to meet requirements of Gradle Android 0.5.4.

Configure maven-publish, add metadata required by Sonatype/MavenCentral.

Modify version to -SNAPSHOT.