This is an implementation of Norvig's spellchecker [1] based
on Joe Sander's port to PHP [2].

Main differences from Joe's try:
- the code is wrapped in an class
- it's working
- i rewired some of the algorhithms to be closer to what Norvig
  suggested

known shortcommings:
- it's slow
- it needs lots of RAM, i run it via the php-cli with a memory 
  limit of 512MB


[1] http://norvig.com/spell-correct.html
[2] http://soundofemotion.com/spellcorrect.txt