Add goog.asserts.assertElement() to JS Compiler assertion functions so we get code removal.
-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=52527693
Minor fixes for the Pretty Printer.
-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=52580327
Merge remote-tracking branch: upstream/master