Granted Noam Raphael's request for minor improvements to the re module and

Granted Noam Raphael's request for minor improvements to the re module and
its documentation.

* Documented that the compiled re methods are supposed to be more full
  featured than their simpilified function counterparts.

* Documented the existing start and stop position arguments for the
  findall() and finditer() methods of compiled regular expression objects.

* Added an optional flags argument to the re.findall() and re.finditer()
  functions.  This aligns their API with that for re.search() and
  re.match().