Framework: Add the ability to enable/disable use of Profiles

This will remove the Profiles item from the Power menu when the user has
selected to disable the use of System Profiles.

TODO: Better handling of returning a default profile when requested

Change-Id: I3c29b1bbd8f72c5432a1906a6b412d9412279c9f

Conflicts:
	policy/src/com/android/internal/policy/impl/GlobalActions.java
Profiles: add PROFILES_STATE_CHANGED_ACTION broadcast intent

Added a new broadcast intent to profiles manager (PROFILES_STATE_CHANGED_ACTION), for
notify an event when profiles are enabled or disabled.

Change-Id: If701b3be54157c23acdf74e1da658fbce335437e
Signed-off-by: Jorge Ruesga <jorge@ruesga.com>