Merge branch 'release-1.2.3' into develop
Add a space after a "throws" clause.
Only set the list adapter if it is not already set.

Should fix an IllegalStateException crash in unregisterDataSetObserver
in the Android framework. See http://crashes.to/s/ae44bec4d3a for
details.
Update to gradle build tools 1.0.0.
Fix a crash constructing Player objects on API < 9.

The hashcode functions call String.getBytes(Charset charset), which
doesn't exist on Android API < 9 (anything below Gingerbread), and
throws an exception.

Check for API < 9, and fallback to String.getBytes("UTF-8"), and
String.getBytes() if that also fails.
Remove extraneous period in a comment.
Prepare for release 1.2.4.
Merge branch 'release-1.2.4'