[krbdev.mit.edu #8163] python test issues

[Tom Yu via RT]

For the shebang lines, we should either eliminate the shebang lines
altogether or fix those three files so the shebang lines come first.
(The places where the shebang line doesn't come first seem to be due to
copyright notices being at the very top of the file.)

Only two of the .py files in that directory have execute permissions,
which is OK for in-tree use.  (We explicitly invoke the python
interpreter.)  It does raise the question of whether we should have the
shebang lines at all.