[crossfire] Crossfire Plugin System v2.0

[Nicolas Weeger]

Yeah for the rewrite!

I haven't checked everything, but I did see previews, so my opinion is
to commit, and fix things as issues arise. *gets his char* to const
char* spell ready* :)

As for breaking compatibility, it isn't too bad imo. As you say, not
*that* many player-owned items with scripts, DMs can handle the fix.

The only drawback of using items in inventory is that, if you want an
archetype to have one (for instance my gps), then you need a special
treasure list to make sure it got the hook - but we can live with that.
And arguably, if it's something needed at archetype level, it should
probably be part of the server core (hum, maybe i should have left my
gps code lol).

The common plugin part is nice, will make it easier to write other
plugins. Kind of like the old libcross, but much cleaner, and more
failure-safe (no calling add_string straight!). It can also make many
checks - though probably the checks should be on the server side for
maximum crash prevention (negative value for a player's Str someone? :p)

The Python object system is pretty good, it'll simplify code and make it
cleared imo.

Ryo