On track listing and track nodes file metadata only shown for FTP'd files

Currently the track node view is just showing all available fields on the podcast_item nodetype. In fact this should be run thru a custom template (or panel page, etc) to show the proper metadata depending on whether the media file is local, remote, or non-existent for some reason.

In normal cases, it shouldn't be too confusing for "normal" users (who either configured FTP access from the beginning and have all media files on their FTP server, or for those who don't use it at all), but it *will* confuse users who have switched from one to another during use of the tool.

Here's a screenshot of a track node to show what I mean: this is how it looks now:

So a future version should only show the actual data used in the XML feed. In the above case, show links and thumbnail for the local values (the filefields and not the link fields)