Custom suggestion: Global Move UI stuf (Middle mouse button)

[mvgulik]

Currently the middle mouse button is hardly used.
1) Main: Panning/changing the camera view. (when MMB is used, click+hold & drag, in the main world view)
2) (not documented) Switches focus to the MMB clicked container(ui). (dupe functionality)
And that's it.

Might be useful to also allows moving ui-stuff around with the MMB.
Like for example container-UI's. (if MMB is clicked 'anywhere' in the targeted ui-window) ... No more accidentally picking of some item, or sending the hearthling on a wild goose chase (like with a LMB click that's juuust outside the ui-window.)
Figure some other potential ui parts for this could be Belt-ui, Tool-bars, .?., and I guess Map-window too.

Best would be if current active custom client maintainers work out the general behavior actions together, instead of each custom client inventing some slightly different wheel.
One problem ... currently I only see one active custom client maintainer ... on the forum that is. ... ie: Hurricane.
- Kami seems to be on an other long real-life marathon.
- Ender don't counts as now a days he only fixes stuff ... sometimes ... and generally don't seems to like to communicate.

Needles to say I don't hold any expectations here. I just dump the idea and observe what happens next (if anything).