* Brought llfilepicker.{cpp,h} up to speed with V3 by adding
FFLOAD_MODEL, FFLOAD_COLLADA, FFLOAD_SCRIPT, FFLOAD_DICTIONARY
However, note that we used FFLOAD_LSL, so I renamed their
FFLOAD_SCRIPT to FFLOAD_LSL and kept our way of filtering.
* Fixed the filter token that is sent to the plugin for
collada (from "dae" to "collada").