pre-cache seqids for -matchdescstart optimization

Closes #363.
overflow prevention
cosmetics
change wording of option description to be more generic
do not allow lone expect() calls
add SO type query capabilities to speck tool
use new functions in example spec
Merge pull request #406 from satta/matchdescstart_precache

pre-cache seqids for -matchdescstart optimization
Merge pull request #407 from satta/sostuff

Add ontology type query support to speck engine