Editor: minor cursor glitches in the Room Editor in Area edit mode

[ivan-mogilko]

Summary: when in Room Editor mouse cursor is not synced with the current editing mode at certain moments when working in any Areas mode. This is not a very serious problem, but an irritating one.

This problem seems to have 2 instances.

1. Since 3.6.1, where the new panning controls were added, the cursor seems to reset to "arrow" each time after performing a drawing operation. For example:

• Select a valid area (hotspot, etc)
• Select "Rectangle" tool.
• Hover cursor above the room, notice that the cursor displays "crosshair".
• Hold down and draw rectangle, then release a button but try to not move the mouse when and after you do.
• Notice that cursor turned into a "arrow" for some reason.
• If you move mouse again, cursor will switch to "crosshair" instantly.

It looks like something breaks in cursor update logic when you release a mouse or finish drawing operation.
This does not happen in previous versions.

2. I did not know about that earlier, but it appears that each drawing tool has a keyboard shortcut. For example, Ctrl + N toggles line drawing, Ctrl + F toggles Fill mode, Ctrl + C is Selection (weirdly enough), and so on.
   Thing is, if you switch to any mode using only keyboard shortcut, the cursor will keep an old look until you move the mouse.
   This is an older error, not a recent regression.
   EDIT: similar problem happens with Alt + LMB combo which i added very recently following a user request (b4a5886). If you hold Alt but not click yet, the cursor does not update, unless you move the mouse around.