wip/runtime2: Drag-rotation doesn't work like it used to with runtime1

wip/runtime2:

Drag-rotation doesn't work like it used to with runtime1 based editor. When drag rotating with right click, it should rotate around camera direction. When drag rotating with left click, rotation should have some logical correspondence to the direction the the mouse is moved like in runtime1 based editor. In all cases parent rotations and camera position/rotation should be taken into account.