Log Message:
Update tkdesk to 2.0.  This version has a problem as shown in PR
pkg/25274, but 1.x didn't build at all since the recent blt update.
perry@ will work on fixing this packge.

Changes:
- Tcl/Tk 8.4 compatibility
- Dropped support for Tcl/Tk 7.x
- Mouse wheel support
- diff support
- Improved configure script
- New TkDesk logo