Bump up targetSdkVersion to 19

Follow the recommendation to use the latest API version. Not doing so will cause devices on later versions to be in compatibility mode. There might be some regressions in the more recent versions.
Bump up target to android-19
Reformat code.

This should get rid of a lot of Checkstyle errors and make the code a little easier to read (and more consistent).

Indents are 4 spaces, spaces around equals signs and operators, and one space after a comma.