Fix ant build

Downgrade android-support-v4.jar to r7. This needs to be kept in sync
with the support library versions used by ActionBarSherlock and
ViewPagerIndicator otherwise jar mismatch errors occur. It would be nice
to update those binaries upstream, but chances are slim that that will
happen anytime soon.

Remove outdated Urban Airship library that was causing "Multiple dex
files define ..." dex errors.