Replace to_build_path() with the more general rebase_path(). Use rebase_path to (finally) make grit paths work properly.

Add more colors to help, yay! I also removed a bunch of colons from headings since they look stupid with the colors.

Add a new variable root_build_dir.

Fix some bugs in the scope_per_file_provider that didn't include the toolchain subdirectory. Add some more tests for this.

Add a --no-exec command-line option to skip executing scripts so one can see how fast things run without forking out to grit and friends.

Add non-Linux build for expat. Other Windows build stuff for SSL, base

BUG=
R=scottmg@chromium.org

Review URL: https://codereview.chromium.org/23618064

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@224747 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 224747