Update to Android Studio 0.4.0 (Gradle 0.7+, wrapper 1.9).

See http://tools.android.com/recent/androidstudio040released.
Merge branch 'develop' into custom-acra
Optionally include the user's e-mail address in error reports.

Support the ACRA acra.user.email preference, and prompt the user to
provide an e-mail address.  Include an English string for the preference.
Use the ACRA "DIALOG" alert method, instead of "NOTIFICATION".

Remove the strings crash_notif_ticker_text, crash_notif_title, and
crash_notif_text, which are no longer required.