TARGET_BUILD_TYPE:

Summary:
Improve TARGET_BUILD_TYPE and also introduce the developer build type
to be used by us shortly.

Test Plan:
Ensure both release and development build types build correctly after updates in other repos (will update
depends)

Reviewers: randall.rushing, synergy

Reviewed By: synergy

Differential Revision: http://review.codefirex.com/D180

Change-Id: I26e4f109222f814842e0b7f487c4529db2f0a11f