Frameworks: tablet powerwidget management (1/2)

Settings: http://review.cyanogenmod.com/#/c/16842/

Adds basic powerwidget management for tablet devices
Allows to setup up to 6 different toggles, or remove all of them

patchset 2: remove whitespaces and tabs
patchset 3: remove some other tabs left
patchset 4: some other tabs were hidden
patchset 5: *changed strings for consistency with phone powerwidget
            *added license header on some files
patchset 6: remove WIP tag

Change-Id: I2e643401aaac0146857abe8c2d2dbc652d28e666