[development] module_exist() / module_exists()

[John VanDyk]

 From http://drupal.org/node/64279#module-exists :

"module_exist() is now module_exists()
For consistency with PHP function_exists, file_exists, etc. That's 
about all there is to say about that. :)"

 From my local copy of cvs:

$ cd /cvs/contributions/modules
$ grep -r module_exist\( . | wc -l
      630

It would be nice to have a wrapper function in for one release cycle.