Several fixes and enhancements:
+ No longer fail due to timeouts or memory limits. And let apache know
that we're a memory hog so it can clean up after us.
+ Add support for user account updates (optional)
+ Add support for user account renames (optional)
+ Cleaned up the logic that deals with creation and failure
+ More robust error handling
+ Use optional_param() -- no longer depends on register_globals
-- when do we switch that off?
+ Added the relevant documentation.