Allow devices to specify certain ro. props via TARGET_INIT_VENDOR_LIB

This modifies buildinfo.sh to not set model, name, description, and
fingerprint in build.prop. These can then be set via custom init
lib.
This also fixes ota_from_target_files to function without these
props being preset.

Change-Id: I945b2c38e60b207d2d0f82b34f4f230ac21b0657

Conflicts:
	core/Makefile
	tools/releasetools/ota_from_target_files
MAKE NOVO & MAGICBROWNIES!

PS2: It's impossible to make Lokesh happy :P
PS3: ERRRR
PS4:Fix everything

This commit is for Lokesh, I really want him to get his builds down to 18 mins. Here's rooting for ya lokesh!

To use: Run "make magicbrownies" and it will clear only the out/target/product folder, for hopefully, faster builds.

Change-Id: I6ff6ffcf7c351cf18d90ab3970b13b806bffed54

Conflicts:
	core/main.mk
Moar clean options!

appclean: clears out all apks
imgclean: clears out all img files
kernelclean: clears out all kernel stuff
systemclean: clears out all system stuff
recoveryclean: clears out all recovery stuff
rootclean: clears out all root stuff

Change-Id: I3b6d9ca53e083385cca3ae66084c5a39901b3d1b
Make it dirty

Change-Id: Iaf28934f4d3c90b681289696cfa9fadb1ae102ec