Fix ExtJS 2.2.1 with IE9+

IE9 introduced the W3C-compliant addEventListener() which can be used instead of the 'ie-deferred-loader' hack that no longer works under IE9+.

Signed-off-by: Max Fierke <fierk007@umn.edu>
Merge pull request #1 from maxfierke/ie9-fix

Fix ExtJS 2.2.1 for IE9+ (addEventListener)