switch to appcompat. b/16664350

Currently only for MailActivity, ComposeActivity,
and FolderSelectionActivity.

Any activity that inherits from ActionBarActivity must
use an Appcompat-derived style. Three styles currently
exist: UnifiedEmail.Appcompat, UnifiedEmail.Appcompat.Toolbar,
and ShortcutWidgetTheme are all based on appcompat.

go/appcompat-material-doc contains the full migration guide.

The fast version is:
All MenuItem-related work that relates to actions must use
the MenuItemCompat-equivalent.
Any theming should use the appcompat versions which don't require
a namespace prefix. For instance, use actionBarStyle instead of
android:actionBarStyle.

There are a few missing styles on views that can't use appcompat versions.
Those still use style overrides for v21 changes. All others use appcompat versions.

A few methods on activity should now use the support equivalents:
getSupportActionBar()
supportInvalidateOptionsMenu()
startSupportActionMode()

Change-Id: Ic6f5964f4115ab4bde49c19df5fe49c9086df965
33 files changed