Refactor MailboxList to use Fragment API

* Moves all list-related implementation to new MailboxListFragment
* One item that remains to be done is to remove the dependency on the
  activity for handling context menu (longpress) in the list.

Change-Id: I7b5769d9d81fb685cf480de3d3e18b4e1c078f2d
Fix for failing SecurityPolicyTests.

This fixes the following exception.

java.lang.UnsupportedOperationException
        at android.test.mock.MockContext.getApplicationContext(MockContext.java:82)

Bug 2725552

Change-Id: Iaca177defe5f5e836211c58270379da056fa64e0
Merge "Fix for failing SecurityPolicyTests."
Controller rework.

- Controller.Result is now a class rather than an interface,
  so subclasses don't have to implement empty methods.

- Replaced Threads with AsyncTasks, which is more light weighted
  because it uses pooled threads.

- Removed the Result argument from Controller's methods.
  These argumetns weren't used, except in serviceCheckMail.

  Regarding serviceCheckMail, the new code behave differenly from the old code.
  If there's already listeners registered when it's colled, they wouldn't get
  called in the old code, but they will in the new code.
  But I think this difference is okay because that's how it works for
  POP/IMAP accounts.

Change-Id: I37a857ce7c089c1a411cb7f1fcfcb72c9f5fd2a6
am 285486a2: (-s ours) am 3ee0cad5: (-s ours) DO NOT MERGE Workaround for KeyguardLock problem
Move account deletion feature to Controller.

Change-Id: Icd3a7cc4ff0db8fb65d3e01868543e7ce8ea79e7
Merge commit '954bcd45b0c9febfb41bb0dc3dde2eca7559a290' into oxygen_1006

* commit '954bcd45b0c9febfb41bb0dc3dde2eca7559a290':
  Move account deletion feature to Controller.
  Controller rework.
  Fix for failing SecurityPolicyTests.
  Refactor MailboxList to use Fragment API

Conflicts:
	src/com/android/email/activity/AccountFolderList.java
	src/com/android/email/activity/MailboxList.java