input filter and integration with insert module (patch attached)

I needed to have an input filter and to insert jplayer anywhere in a node body. I needed to have an insert button in the field too to make it easier.

I think this would be cool to have that in jplayer module. So I wrote a patch for that.

To work correctely it is necessary to check the jplayer filter in admin/config/content/formats and to check jplayer insert style in the jplayer field configuration.