[PATCH] Teach zorg to support cmake and modules for Clang builders

[David Blaikie]

Looks good. One optional comment

(wow, phab markup does fun things with leading #... )

================
Comment at: zorg/buildbot/builders/ClangBuilder.py:332
@@ +331,3 @@
+    #
+    # It does not make sense to skip this for a bootstrap builder,
+    # and we don't support doing so for cmake builds.
----------------
Maybe rephrase this (it leaves fairly ambiguous as to why we want to clean for the configure build here - the answer being "there's no known reason") maybe:

# FIXME: verify that there's no need to skip cleaning for the configure stage 2 build (it doesn't make much sense) and remove this condition

?

http://reviews.llvm.org/D4936