unmarshallable objects.

Rework --with-readline and --with-thread.

Updated some comments.
Fixed bug in Merge() called with NULL args.
Get rid of TkDefaultAppName() -- it is not used anywhere.
Pass error message on when Appinit fails.
Create/Delete FileHandler assume fd is a socket on Windows.

Use PyArg_ParseTuple() where it makes sense.

WNOHANG set.