[developers] morphology check in

[Ann Copestake]

The new code checked in has a simpler and more verifiable version of the rule
fsm construction but it is slower in some cases.  However, I have, I think,
removed any need to construct a reachability table from all the rules, in
favour of a table with only things that are not spelling rules.  This is very
fast to construct for the ERG and the German grammar. As far as I can see,
there is never any need for a check for a linkage that can involve intermediate
spelling rules, since they will always be postulated by the morphophonology.  A
possible exception is if an external morphophonological engine is being called
which delivers a partial tree in the way the old LKB morphophonology did, but
in that case the existing code can be uncommented.

The current ERG needs to be fixed with respect to the escaping of characters in
the morph rules.  And I am also worried by all the cycles ... So apart from
testing it loads and parses something, I have tested on the April version of
the grammar again.

Ann