Fix plupload panel on IE < 10

Fix relative URL for flash and silverlight resources on plupload panel (these URLs are different in release deployment than the debug environment)
Media content on plupload panel fixes

* Move plupload media content to a new media folder
* Use this folder on configuration
Merge branch 'plupload_IE9_release_2' of git://github.com/alediator/mapstore into alediator-plupload_IE9_release_2
Merge branch 'alediator-plupload_IE9_release_2'