Rework lambda-theory scripts to use new varying parameter recursion theorem.

Also make work for myself by having some of the script files use
'tight' equality. Later files get switched back to loose (prec = 100)
equality, because it was all getting to be too much work.

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).