cr-linux debug should use clang and maybe be a components build

cr-linux debug should use clang and maybe be a components build
https://bugs.webkit.org/show_bug.cgi?id=108512

Patch by Alan Cutter <alancutter@chromium.org> on 2013-02-13
Reviewed by Adam Barth.

Modified GCE cr-linux-debug-ews bot build scripts to configure clang over gcc for build performance.
Build bots will update clang with each bot cycle.
Updated GCE image paths to suit gcutil 1.6.1.

* EWSTools/GoogleComputeEngine/build-chromium-ews.sh:
* EWSTools/GoogleComputeEngine/build-commit-queue.sh:
* EWSTools/GoogleComputeEngine/build-cr-linux-debug-ews.sh:
* EWSTools/GoogleComputeEngine/build-feeder-style-sheriffbot.sh:
* EWSTools/configure-clang-linux.sh: Copied from Tools/EWSTools/GoogleComputeEngine/build-chromium-ews.sh.
* EWSTools/start-queue.sh:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@142802 268f45cc-cd09-0410-ab3c-d52691b4dbfc