Updating to Rangy 1.3 alpha

We previously tried Rangy 1.3 alpha but rolled back due to a bug
with getting cursor position in IE. Rangy developer Tim Down fixed
the issue here:
https://code.google.com/p/rangy/source/detail?r=780

Both 1.2 (filenames without file versions) and 1.3 in the repo
for now.

Change-Id: I26263fc1d10e3c2bdda7f1c9135544ca3bc05d97
Merge "Updating to Rangy 1.3 alpha"