skdiff: recurse over subdirectories, unless --norecurse option is given
in anticipation of https://code.google.com/p/skia/issues/detail?id=743 ('move gm baselines outside of trunk, and modify naming convention')
Review URL: https://codereview.appspot.com/6465053

git-svn-id: http://skia.googlecode.com/svn/trunk@5121 2bbb7eff-a529-9590-31e7-b0007b416f81
28 files changed