[1/2] Base: Speed up booting on multicore devices

- Add multithreading support to Installer/installd
- Parallelize package scanning
- Parallelize boot dexopt

Change-Id: Ia6b815bde0e5cdf996fdfdec3ba228bcde9e4e0b
Base: Correct MV to mV on QS back battery tile

Change-Id: I835f28b432570ea14775f93030599cf8731e9b76
Merge "[1/2] Base: Speed up booting on multicore devices" into android-4.4
merge changes from Omni 4.4 into local branch