Original patch by Tal Einat.

revised by R. David Murray.

Before, if a default was set on the parent parser, any default for that
variable set via set_defaults on a subparser would be ignored.  Now
the subparser set_defaults is honored.

Patch by Jyrki Pullianinen.

when compiled with VS 2010 or above.  Initial patch by Tabrez Mohammed.

htests to add # htest # marker for coveragepy and stop tcl errors.

Move test lines up with respect to icons.

a filename, pop up the Open Module box. If a module is opened, open a
corresponding browser.

easily recognize and display boolean values as such and recognize changes.
Also reformat comments and alphabetize extensions included with Idle.