up to v20130722 (July 22, 2013)

- Stricter missing-property checks for structs.
- Improved type inference for assignments to the prototype property.
- Fix incompatibility between removeUnusedClassProperties and Object.seal, and add the pass to advanced optimizations.
- Open source the code-coverage instrumentation pass.
- Allow constructors with a declared return type to be called without new.
- Bugfixes for goog.inherits used with generic types.
- Better detection of block comments that contain jsdoc tags.
- In ES5 mode, don't quote object literal keys when they're ES3 keywords.
- In ES3 mode, allow ES3 keywords as property names but quote them.
- New jsdoc tag @disposes for use with CheckEventfulDisposal pass to specify particular arguments of a function to be disposed.
- Updated externs for angular, jquery and maps api.
- Fix issue 1017, issue 1020, issue 1021, issue 1023, issue 1030, issue 1033, issue 1035, issue 1042, issue 1043.

https://code.google.com/p/closure-compiler/wiki/Releases