Invert theme

Use light theme as a stopgap readibility fix until this gets a
Material overhaul

Change-Id: I5f77d96daee34700d3cea7bd4e07728fdc3ca2d2
Update the Superuser settings drawable

Change-Id: I9057b5fc18d2669b29c9e8dde1b121c23cb57744
Merge branch 'cm-12.0' of https://github.com/CyanogenMod/Superuser into cm-12.0