Notes on the abella code
Revert "Notes on the abella code" -- notes moved to a wiki page

This reverts commit 0d7870bb27b5ab14287ab772e4bd69544e0ae7bd.
Move OMakeroot to examples in preparation for branch merge
Merge branch 'hh_omega'
Make web pages buildable again

- Fixed the OMakefile so that it can build
- Renamed hhw to higher-order
- Renamed debruijn_hohh to debruijn to avoid the nonstandard "hohh"