M CallTips.py
Calltip fetch was erroring when an Edit window was used without a Shell.
Also, fix CallTipWindow.py so test code will run and add a comment about a
bug which causes the calltip window to override all others.
Rev 1.4
SF bug 546078: IDLE calltips cause application error.
Assorted crashes on Windows and Linux when trying to display a very
long calltip, most likely a Tk bug. Wormed around by clamping the
calltip display to a maximum of 79 characters (why 79? why not ...).
Bugfix candidate, for all Python releases.
Rev 1.5
Remove unnecessary imports