Hide console mouse cursor when ui_mouse is 0

[daftmugi]

When ui_mouse is set to 0 and using the console:

• Hides the mouse cursor.
• Disables click and select events, so the user isn't surprised by them working when the mouse cursor is hidden.

This is related to #130.

[andrei-drexler]

I appreciate the consistency, but I don't think that's a good enough reason to disable the click & select functionality (which I consider very useful and plan to further extend/take advantage of in the future), especially since there's no alternative to it.