... mainly bittorrent:// and bittorrent://x
The BitTorrent URL is supposed to contain an embedded URL pointing to a
metainfo file. If this is not the case a "custom" error message will be
shown. Also fixes calling of free_list() on an uninitialized list.
Closes bug 729.
Mostly non-ANSI function declarations, using 0 as NULL and inline
function prototypes. Also removed unused S_HTTP_100 network state
enum type, which text message contained unknown escape sequence: '\?'.