Email: Add new check frequency options

Adds 2h, 4h & 1day option

Change-Id: Id49411bab22446d45328292eb7385b660b2ff0e7
Email: Don't fetch deleted messages from IMAP folder

Fetching messages from an IMAP folder within a specific date range returns
messages marked as deleted, also. Unlike every other getMessages() method,
which filter out deleted messages.
This leaves server deleted messages untouched in the mail conversation
view, even when the folder is synced manually.

This patch adds "NOT DELETED" to the IMAP search command, when searching
for mails in a given date range.

Change-Id: I5cc68ab6be6c078252138bb13e5b0e4aab95e648
Email: NPE while checking incoming settings

Fix: onCancel method of error dialog fragment is overridden
     and shows incomming settings when dialog is cancelled.

Change-Id: I6775bc4823d0c10bd3272d231064c5ee27db7920
Email: Add notify for every message

Since Email now uses UnifiedEmail, this setting defaults to false
and there is no way to enable it.
This commit adds this option, which is then honored by
the unified notification engine

Change-Id: I207482d18d13b272cd1b0bd7cec4b3a0d923fe81