URDB-0.99-r277 released

URDB is a universal reversible debugger that can add reversibility to
almost any debugger through a python-based wrapper. URDB is still
experimental. It currently has four personality modules, which
support: gdb; MATLAB; python (pdb); and perl (perl -d).

This is the first URDB release that uses DMTCP revision 784. Reverse-watchpoint is now working for gdb, MATLAB and python. Stress testing reverse-finish is still frail for python and MATLAB.