Fixes for these examples, and an updated MANIFEST/README in
other-models. The other-models directory had become particularly
stale. I obviously need to check that it works more often. (Main
problem: change to behaviour of Q.INST.)

Completely reorganise these files into some sensible directories.
Also, add a file demonstrating that the McKinna-Pollack two-sorted raw
syntax does indeed behave properly (links appropriately to beta over
quotiented terms).