gps: Add loc_eng_set_privacy function to enable/disable GPS privacy lock.

Privacy lock is enabled on loc_eng_init, disabled on loc_eng_cleanup,
mimicking the behavior of TW.  Requires system property
ro.gps.set_privacy=1 to enable/disable privacy lock.

The privacy lock state is non-volatile, and control of the lock is needed
to ensure that the GPS works and is responsive to requests.  Otherwise the
GPS may silently cease to work depending on its last state in TW.

From CyanogenMod/android_device_samsung_msm8960-common:
     9ff42f389529b95a6a234da7142c79594c297a1b

Conflicts:
	gps/libloc_api_50001/loc_eng.cpp
	gps/libloc_api_50001/loc_eng_log.cpp
	gps/libloc_api_50001/loc_eng_msg_id.h

Change-Id: I7401cc9bec75430646944971d20270f97a5043bc
jf: add txt_murata

Change-Id: I4eb760b963e4fea6df9a31f8235d0f9699eb0258
jf:enable the world phone menu

Change-Id: I524ff7196d9f3ae268178826b986d5dcee1de85f
jf: fix world mode chioces

Change-Id: Ib16e47ac3658a1e19e520bbb456dcd6c279f49b4