This patch is base on the work done by Oguz Kayral in the summer of 
2009. Tom Tromey and Phil Muldoon also provided a lot of help and 
guidance on this.

It adds to the python API the module 'gdb.events'. The events module 
contains references to event registries that one can add observers to. 
Namely,
    events.breakpoint
    events.signal
    events.cont
    events.exited

I have also taken the example that Oguz provided and turned that into a 
test case.

This has been tested on Fedora 13 X8664 with gcc 4.4.4-f13

A documentation patch will follow soon.

Thanks in advance for the review.

Sami