vendor: support custom unofficial build tags

By defining TARGET_UNOFFICIAL_BUILD_ID in a device's cm.mk, users can
build custom CM builds with their own identifier in place.
This adheres to CM's policy that unofficial builds must be
marked as such, as both the filename and internal version will still
contain the word UNOFFICIAL.

Example:
TARGET_UNOFFICIAL_BUILD_ID := CatEater01
results in
cm-11-20131211-UNOFFICIAL-CatEater01-device(.zip)

Change-Id: I61acdf4698a7fe2b35d3d5315be4b444b1b97987
overlay: Fix Keyguard configuration

In 4.4 Keyguard has moved to a separate package
Move its config options to the proper overlay

Change-Id: I0a57874f3ef7702c6407485e98e1d10169baa0ac
Merge "overlay: Fix Keyguard configuration" into cm-11.0
Merge "vendor: support custom unofficial build tags" into cm-11.0
.gitignore - add proprietary folder

Change-Id: I128b8191328db5ed8acde408ccb0d063d3c2f17b
Add KT/SKT spn value

Change-Id: I461eaa31d84fc1f494839aad591564d9875aefed
Add more audio files

Change-Id: I10d5bcd0c2a46e16438c3a46d94d8ac596a71e1a
Remove Launcher3 from the build

Change-Id: If946b4371288b6182c0f24e11ea7014035e8d3e1
Add HALO to the build

Change-Id: Id7646cf6b7aee6cda14bcd5de232d8a38c6fd924
Add ScreenRecorder and libscreenrecorder to the build

Change-Id: I84137a72914ac4f266976f6f17b04f09e138afbe
Remove CMUpdater from the build

Change-Id: Ic71bc2360605bda4c9f55eed80c39d2801750692
Enable gesture typing - (2/3) - add prebuilt lib

Change-Id: Ia8d90975c4aa842269f2f3fcd1b8decf90a48b47

Conflicts:
	config/common.mk