Update to r19 of the Android Support Library. Needed for #99

Signed-off-by: Greg Meiste <greg.meiste@gmail.com>
Replace ViewPagerIndicator with PagerTabStrip. Closes #99

By using the Android Support Library's PagerTabStrip, the
ViewPagerIndicator can be removed, resulting in one less
dependency.

Signed-off-by: Greg Meiste <greg.meiste@gmail.com>
Simplify to one main layout

Having three main layouts where the only difference was the ad
size didn't make sense. Change to have one main layout and get
the ad size from size specific values files instead. This will
make layout changes easier in the future.

Signed-off-by: Greg Meiste <greg.meiste@gmail.com>