* librb is no longer a separately configured subproject.
* charybdis is now a standalone directory with a binary.
* Include path layout now requires a directory ircd/ rb/ etc.
nenolod gave the thumbs-up to port ircd-seven banfowards to charybdis to spb
for a while, and people have asked about it. Might as well do it since it's a
slow weekend.
Note that as a side effect use_forward is removed from the config and
unconditionally enabled!