Fix test failure for test_tcl on OS/X and Windows if a
version of Tcl other than ActiveTcl is installed (ActiveTcl
included TclX, other Tcl distros didn't).

I'm removing the package loading test because it's hard to
come up with a package that is guaranteed to be in any Tcl installation.

Special-casing darwin and windows is ok since that leaves the
only Tk platform (X) which the test was trying to address.
1 file changed