Various changes to handler.py

It only imports re.compile, rather than the entire re module.

Handler:
Added the missing comma in __str__()'s format string.

HandlerManager:
add_handlers() now sorts the Handler lists that were added to, eliminating the need for a sort_handlers() . Sorting was also unreversed.
remove_handlers() now takes actual Handlers to remove, rather than IDs. It also removes empty Handler lists.
sort_handlers() and print_handlers() were removed.

All of it now fits in 79 columns. :)