Support reading since_epoch and secondary brightness files

TWFunc::Fixup_Time_On_Boot: Will now try to read
/sys/class/rtc/rtc0/since_epoch to correct time, if that fails
it will try to use the ats files to correct time.

TWFunc::Set_Brightness: One single function to set brightness
from both the automated functions and the gui actions. It is
able to set a second brightness path if present, it will set
them both the same value. Many Sony devices have 2 brightness
files in the sysfs that must be set to properly set the
brightness.

Change-Id: I7ca582109085dfbcb46b8de73ad031e4b7903fca