update copyright to 2013
update has identifiers to be more consistent with has.js
add notes about poly/setImmediate to README
ensure we're using the correct global object in all environments and remove code to try to shim the global object's prototype (since we don't do that in other shims)
stricter checks for existing implementations
remove IE6-8 attachEvent code since this code branch will never execute in those browsers
stop abusing NobleJS's namespace
update version to 0.5.2
add bower.json
add release notes
fix typos in README
Try to shim Object.getOwnPropertyDecriptor and Object.defineProperty in IE8