Ctrl+Shift+RClick places move WP instead of calling the special WP dialog (low priority)

[MiC17]

This is the 2. point from #39 .

Pretty easy to reproduce: Spawn a single infantry unit and try giving it a mix of MOVE and special waypoints.
Most of the time the dialog will appear no problem, but sometimes it won't, instead placing a MOVE WP.
It feels as though this happens more often when WPs are placed in rapid succession (1 every 2 seconds).

This is low priority as the nature of the WPs in the menu make it a rare occurence that you have to queue several of them.

[chessmaster42]

I have a pretty good idea of why this is happening and it's related to some code that causes the custom handler to take just a few seconds to set itself up. Rapidly placing waypoints will of course break this but right now I'm still focusing on performance and bugfixing so I think I can fix this.