filetype.c has been changed to get the MIME type of a file from the MIMETYPE tooltype
of the icon or default icon for the file. The install script will set the basic of
these, and icons for default.css and AdBlock.css have been added to ensure these
always return the correct MIME type.
If the MIMETYPE tooltype is not found, the code will use datatypes.library to identify
the file and make a guess as to what the MIME type is.
svn path=/trunk/netsurf/; revision=5651
