Fix infinite recursion in Au formatting

Polymorphism strikes again.  This should have been **obj but let's switch to an
explicit pattern match to be safe.

Fixes #1172.
Update rust-opengles for bugfix
Merge pull request #1181 from kmcallister/opengles

Update rust-opengles for bugfix
auto merge of #1174 : kmcallister/servo/au, r=larsbergstrom

Polymorphism strikes again.  This should have been **obj but let's switch to an
explicit pattern match to be safe.

Fixes #1172.

r? @larsbergstrom
First attempt at making a testharness.js test run under make check-content.
Update.
Possibly more output.