Support building toolchain inline

Summary:
Build the arm-linux-androideabi toolchain inline by default for development build types. Depends on D193  Depends on D188 . There were other changes that this needed, but they've already been pushed due to no issues with the current source.

Here are some features:

  - Use TARGET_CPU_VARIANT to tailor the toolchain for the target device.
  - Use a squashed patch file to patch gcc trunk so the gcc repo may stay more pure (easier to maintain).
  - You may use choosecombo instead of lunch to avoid using an inline toolchain. In this case it builds with a prebuilt 4.8 arm-linux-androideabi toolchain.
  - Utilizes the ABS function "overload" delay to echo toolchain info so we don't need to use a wait to allow the developer to see them.

Test Plan: Test that your devices work well with this commit and it's patch set. Be sure to check all depends and apply multiple patches on top of one another with arc patch DBLAH --nobranch

Reviewers: randall.rushing, Mustaavalkosta, michyprima, rlasalle15, Roach

Differential Revision: http://review.codefirex.com/D194

Change-Id: I4ee21c29cc79411c6493955ce568404b671fa7c8