Get swapTheory to build.

This stuff is probably moving to the 'not worth maintaining' category.

Removed trailing whitespace from all .sml and .sig files.

This affects over 900 files and was done using emacs's delete-trailing-whitespace
function in batch mode. Building the system with Poly/ML and Moscow ML seems to
work, so I'm hoping these changes don't break anything. Please complain if
they do!

Recast binderLib's internal databases about "binder"-information for
types. In the process, give up on the attempt to make this technology
work for the "old" style of recursion theorem as in my TPHOLs paper.
Now the only style supported is the quotient + nominal proof (which is
what is in barendregt).

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.)

A whole mess of small changes intended
at making simpsets prettyprint informatively
in the interactive loop. Very possibly
I haven't updated all the files in the examples
directories.

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).