Remove TABs from examples

Repaired the STE example to build with Kananaskis-6; it was broken.
Now, after doing "Holmake" in the main STE directory, one can run the examples by

hol < RunScript

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!

Symbolic Trajectory Evaluation example from Ashish Darbari.