ROMControl: Remove Needless Preference

Was planning on doing this with the
        multiple custom toggles patch
        but I've run out of energy
        on that idea for the time
        being.  Probably a good time
        to do so now.

Change-Id: I6dac8c2a40efba6c60c337307f7fc724757041f3
Add CM10.1 LockClock option

Change-Id: I0e069887f5bc66bf44c644dea58b3cdd7d14f268
bring back DPI changer

originally part of DPI Changer + Tablet UI commit on ICS by @sethyx and @dagr8
cherry-picked and adapted for JB-MR1 by @championswimmer and @kecinzer

PS4:Added situation that values don't exists in build.prop
PS5:
After hour of play with this condition in IntelliJ IDEA I finaly found solution for it.
I must compare .lengtg() to 0. Now it works.
Still I think, that we need clean up all dialog, because clearing Market stuff is no logner needed.

PS6: we are keeping the long procedure intact because we never know
if some day play store starts checking persis.lcd_density too,
so let's keep the compatibility workarounds,
even though atm they are not needed

Change-Id: I3e3a63eb64b0f107c1fad0f2fd8bb7c7f6e6e227
Signed-off-by: ChampionSwimmer <android@championswimmer.tk>