Added horizontal gravity support / only handle back key for hiding

Change-Id: I845598bb706089c788e8d829d7d4ebfb9998eb99
OmniSwitch: quick switcher

-added back button support
-added quick switcher settings
-added quick switcher button config

PS10:
-fixed division by zero - thanks Juan
-added item limit preference

PS11:
-quick switcher depends on drag handle
-fix drag handle switch
-next try - division by zero fix - thanks Menno

PS12:
-fixed timing issue - thanks Cory

PS13:
-added showcase for quick switcher
-remove start and stop service broadcaset and
INTERACT_ACROSS_USERS_FULL permissions since we dont
need it anymore with the simplified recents integration
requires https://gerrit.omnirom.org/6953
-listem to ACTION_SHUTDOWN intent to save local prefs
-fixed back key handling

PS14:
-added ordering support for action buttons - coudnt resist :)

PS15:
-tweaking horizontal scroller

PS16:
-uprev version

Change-Id: I845598bb706089c788e8d829d7d4ebfb7928eb73
OmniSwitch: Immersive mode button

PS13:
-make image a little bit smaller to match the rest
-cleanup

PS14:
-more cleanup

Change-Id: Ief338c252f0c7b9819040a48cc374d1f208854cc
OmniSwitch: FR translation

PS2-4: rebase and add translation
PS5: correction

Change-Id: I69737662768f122aa72f5962106df1a8298c167b
OmniSwitch: center action buttons again

Change-Id: Ida6292d1cdcab26094f49b8fa06877caf5795bc7
Merge remote-tracking branch 'du/du44' into vaosp

Conflicts:
	src/org/omnirom/omniswitch/SwitchService.java