in addition:
- fix AND-OR precedence in cursor query in MessageList.
- move special mailbox ids from MessageList to Mailbox
- move shared code from MessageList to com.android.email.Utility
- add invisible prev/next to landscape in order to avoid special-case in code
- select mailbox list using IN() instead of list of OR
Note: Checked in by Andy to facilitate further work on MessageView.
Change-Id: I8049be2b45fed1e4e697a0ed895492c4d0e59e0a