Mouse down vs mouse released

[axx0]

Currently mouse orders on the map are issued with Input.IsMouseButtonDown in BaseControl.
This may cause multiple unnecessary calls to functions while the button is down (at least that's what I noticed doing some tests).
Most mouse orders in original game are issued only when the button is released, the two exceptions I noticed are Goto orders on units and clicking on the game menu.
So simply replacing IsMouseButtonDown with IsMouseButtonReleased probably isn't the best solution. Some sort of distinction between both calls should be made.