Build: Add support for specifying build variant in brunch/breakfast

This little modification allows specifying build variant in brunch/breakfast commands. For example we can use "brunch i9300 user" to build user variant instead of default userdebug.

When no extra argument is given, userdebug is default.

Conflicts:
	envsetup.sh

Change-Id: I2d438209f8a14949c64baa66485c811da384d20b
full_base.mk: Don't compile OpenWnn.

This package is/was meant to be optional.

Change-Id: I41f9b7c6dab50fbaf7ba4e90c22f731e7e8cbce2
Merge "Build: Add support for specifying build variant in brunch/breakfast" into du-44
Merge "full_base.mk: Don't compile OpenWnn." into du-44