Fix plane app's ability to find the root block after language switch (broken in previous CL).  Fix turtle/rabbit icons in turtle app (broken due to addition of camera icon).  Delete SVG icon file that makes all icons blurry and restore crisper version (binary not in review).
Review URL: https://codereview.appspot.com/10723043

git-svn-id: http://blockly.googlecode.com/svn/trunk@1078 c400ca83-b69d-9dd7-9705-49c6b8615e23