ext/gnomevfs/: Use gst_tag_freeform_string_to_utf8() here, which also takes into account any character sets specified...

Original commit message from CVS:
* ext/gnomevfs/Makefile.am:
* ext/gnomevfs/gstgnomevfssrc.c: (gst_gnome_vfs_src_unicodify):
Use gst_tag_freeform_string_to_utf8() here, which also takes
into account any character sets specified by the user via
environment variables.