build: Add support for extra kernel build variables

 * This allows specifying a variant defconfig, and an selinux defconfig
   which are simply configuration fragments.

Change-Id: I97882ae3b8c2e16ff6a7dce8dd3a70d70f8aa866
fix path to sounds in sdk product

This is necessary to build the SDK:

    lunch sdk-eng && make sdk

Change-Id: I7b9dcfc418ddc46e2967b627525d042bbf6334e1
The bash completion stuff is crapping out on darwin. Disabling.
Let me know if I am doing something wrong.

Change-Id: I6f61f869140b26db0a119617b353e0952eeaebeb
Check bash version instead of OS for bash completion

The bash completion script requires bash 4.0

Change-Id: Id81a42585b1d2cb568cb1b8f602f2bb447bef214
Consolidate bash version checks

There were two checks for bash version, the 2nd was superfluous; this
patch removes the duplicate checks, and shifts the bash version check to
being back after the "are we in bash" check.

Change-Id: I57ff8c1fedce80f739c06643d2976d2c1465db1b
Add support for cross compiling Windows tools on Darwin.

Change-Id: I71372543e8da02e1d2437d6da7eb46b0a72c9870
Merge remote-tracking branch 'upstream/jb-mr1' into jb-mr1