more example progs cleanup.
If python not installed, don't link python!
Merge pull request #182 from linas/link-fix

If python not installed, don't link python!
build-knobs: defer calculation
knob building: optimize perm creation.

Build a complete array of permitted pairs, as before.  However,
don't bother creating the combo tree until we actually select a pair.
This should save both a lot of RAM and CPU cycles.
Merge pull request #183 from linas/moses

Moses knob building optimization