I try to revamp this issue by attaching a new patch which improves the
work I did against asyncore last time.
The approach proposed in this new patch is the same used in the upcoming
pyftpdlib 0.5.0 version which has been largely tested and benchmarked.
In my opinion, without the addition of an eventual paired heap module
into the stdlib there are no significant faster ways to do this than
using the common heapq module.
The patch in attachment includes:

- various changes which improve the speed execution when operating
against the heap.
- a larger test suite.
- documentation for the new class and its methods.

Josiah, do you have some time to review this?