Temporary fix to delete assemblies before adding

Added some temprorary code to delete any of the embeded assemblies
(log4net.dll & Platinum.Managed.dll) before attempting to write them to
disk.
This is just to ensure they are definitely replaced while we're trying
to sort out the file not found issues.
First rough cut of BrowseMetadata

A first very rough cut of a BrowseMetadata implementation. Its for
testing, I've no idea if it'll work or not.
Added well known All Playlists container - 13

Added well known container Playlist and its well know children "All
Playlists" and "Playlists Folder". Both of these are just returning
empty collections for their children, but it means that when WMP
requests well known container 13 "All Playlists", we don't have to
recursively load the entire data model in order to search for it.
Also removed unrequired test code that was setting xml string to a local
variable to assist with debugging.