Add gdb-style signal handling

Add watchpoints. (Mentioned in pdbimprovements)

The main pydb.py file size has been reduced but it is still bit
large. If we can break out into more files that might be nice.

Some more regression tests should to be written. They've been
invaluable so far and maintain quality. Especially for the large
changes.

Redo post_mortem, pm, set_step to funnel through parse_options rather
than taking the optional cmdfile and opts paramaters.

gdb return command relies on the existance of a return statement in
the code.

Add online debugger concept help and in LaTeX? 

There seem to be weirdnesses in the debugger that I don't fully
comprehend and I think they exist in pdb.py as well.

Should check into getting this integrated with ipython's "run -d".  It
has a history mechanism and pydb should too. If it is possible to use
a class form ipython or a class that's out there, that should be done.

The examine command needs to deal with arbitrary objects better.

Use inspect module get_stack rather than bdb's?

$Id: TODO,v 1.9 2006/07/25 01:30:22 rockyb Exp $
