Settings : Add preference for proximity wake

Change-Id: I2fcbdee3bcf33f8e44b6c5fa29fb1d4d6dcab8e4
Signed-off-by: scott <scott@ubuntu>

Conflicts:
	res/values/cm_strings.xml
	res/xml/display_settings.xml
Proximity Wake-Up : adjust strings

Change-Id: I605a11b5bd7150b2a456d5c355af49fd7047e173
make proximity opt in

Change-Id: I26263cfea35bbea6c7644e31cd7ced28f2b0880c
Signed-off-by: scott <scott@ubuntu>