Overlay updates

* Enable install non market apps
* Disable touch/lockscreen audio
* Disable haptic feedback

* Disable homescreen scrolling wallpaper
Hammerhead: enable echo cancellation for voice communication

This greatly improves the quality of VoIP calls, tested on the app
"LINE". Without this, the other party will be able to hear echo
of their own voice.

Reference:
http://source.android.com/devices/audio_implement.html#preprocessing
Clean up the source code

* Add ramdisk folder
* Add prebuilt folder
* Move some files to ramdisk or prebuilt
* Cleanup
spn-conf.xml moved to prebuilt folder after cleaned up.
Move audio_effects.conf to the right place
Merge remote-tracking branch 'upstream/cm-12.0' into cm-12.0
Merge branch 'cm-12.0' of https://github.com/Fagyi/android_device_lge_hammerhead into cm-12.0

Conflicts:
	BoardConfig.mk
	device.mk
	overlay/frameworks/base/packages/SettingsProvider/res/values/defaults.xml
	overlay/packages/apps/Trebuchet/res/values/preferences_defaults.xml