Update the notification icons for Lollipop

Repurposes one of the existing drawables and
includes a new drawable for multiple emails
inspired by the one used in the Gmail app

Change-Id: Ieb8589f38113e55d0170dcd204cd4f25ec2165ea
Change the Email widget to orange

Also update the update the widget preview
with the new look

Change-Id: I5a6571c1b1fec59ca42627ea404cb46c92eb7365
Fix the color of the Compose FAB

Also render it with mostly vector drawables

Change-Id: Ib19c0b4093a7c581481f7cab3c8b92fcf84f5b13
Theming fixes.

Make Toolbar primary text white, and give compose FAB a meaningful
elevation.

Change-Id: Icce5ca70e1196ab511e3426451b1edd1c4c59680
UnifiedEmail: Add native heads up support per account (2/2)

Add native heads up notification support. User can set on every account
if he or she want this account as heads up notification or not.

This patch adds the settings for it as well the complete handling. Due
of a half broken NotificationCompat.Builder class we switch here to the
Notification.Builder class to get access to the methods we need. This is no
problem here due that we do not need compatibility on lower API's

Change-Id: I32cd1b914777dd3a491ab20fe681d347a9d81e3c