Don’t Save Corrupted Blocks Files.

Fix Trac #572, make sure that corrupted blocks files are not
over-written.

Change-Id: I4fddf17eae6229c4d1a7c97154af7a314a526215
Remove IE Support.

Remove IE from the GWT compilation list as well as indicate that it is
not supported in “index.html.” People attempting to use IE will now
get a message listing the supported browsers. We can undo this when we
have IE support working.

Change-Id: Ib2728c7a180b8ac3e409370319032d013d5ed8c8