Allow user to extend nested request attributes like headers without loosing topics.

Use deep flag when extending the request object created by grailsEvents
to allow the user to extend/override request attributes like headers
without loosing information provided by grailsEvents.
upgrade dependencies
add unregisterHandler(s)
Merge pull request #25 from sbuettner/master

Support custom request attributes without loosing the information provided by grailsEvents
minor configuration optimization
urgent fix
urgent fix
Update src/java/org/grails/plugin/platform/events/push/EventsPushHandler.java

removed hardcoded response content-type definition (application/javascript) because this broke streaming for internet explorer (asking to download eventbus.js instead of reading the streamed payload).

no problems with websockets in ff/chrome and no problems with streaming in ie/ff/chrome could be observed without that line. if i understood it correctly, atmosphere handles the browser specific content-type stuff anyways.
Merge pull request #27 from zyro23/patch-1

removed hardcoded response content-type definition in the EventsPushHandler
Update EventsPushGrailsPlugin.groovy

null-safe config querying
Merge pull request #28 from zyro23/patch-2

fixed EventsPushGrailsPlugin throwing npe when custom initParams are defined because of non-null-safe config querying
- merged @zyro fixes
- add connection listener bridge ( to publish on browser:// namespace )
- merged @zyro fixes
- add connection listener bridge ( to publish on browser:// namespace )
update atmosphere js to latest snapshot