PATCH: filters (against 1.2pre2)

[Emmanuel <e allaud wanadoo fr>]

	Hi all,
basically it's just the port of the old patch to 1.2pre2. I've corrected a
certain number of bugs.
Anyway it's still only for testing purpose in order for me to have feedback
on bugs, UI problems, suggestions...
WARNING : Filtering big mailboxes (>500 messages) is very slow! So test it
on mailbox with a few hundreds of message is much prudent.
By the way if someone could review the code in filter.c that does the
actual filtering and tell me about obvious performance gain, he will have
all my consideration :)
You have three patches : libbalsa-filters-1.2-pre2.patch,src-filters-1.2pre2.patch,libmutt-filters-1.2pre2.patch
(this one is a minor one to correct a compile bug).
Christophe has put them at the following urls :
http://ufies.org/~christophe/emmanuel/libbalsa-filters-1.2pre2.patch
http://ufies.org/~christophe/emmanuel/src-filters-1.2pre2.patch
http://ufies.org/~christophe/emmanuel/libmutt-filters-1.2pre2.patch
Thanks
Bye
Manu