[2/2] init: support using old property system via makefile flag

* In 4.4, Google switched to new property system which is based on
  binary tree instead of array of strings. It is faster, but old
  updater-binaries in ZIP files flashed in recovery are not compatible
  with new system, causing inability to flash older ZIPs in TWRP built
  in 4.4 tree.
* This patch backports old system into standalone file and modifies
  the header to be compatible with both
* To turn this on, specify following in device's BoardConfig.mk:

    BUILD_OLD_SYS_PROPS := true
    COMMON_GLOBAL_CFLAGS += -DBUILD_OLD_SYS_PROPS

Signed-off-by: Vojtech Bocek <vbocek@gmail.com>

Change-Id: Ie77897eb2f5a7a4d835cb0ad3405bd205a579c40