Instead of requiring the tester to manually add the path to the python-gdb.py
file in the checkout to their .gdbinit file, add it automatically when
invoking gdb in the test.

Instead of requiring the tester to manually add the path to the python-gdb.py
file in the checkout to their .gdbinit file, add it automatically when
invoking gdb in the test.

Patch by Janne Karila.

Patch by Berker Peksag.

Patch by Marek Šuppa.

with certain versions of Tk 8.5.  Initial patch by Kevin Walzer.

Patch by Brent Tubbs.

Patch by Brent Tubbs.