Fixes #1 Inputs can't be clicked for focus

- This needs to be addressed further. It's unclear if this
solution will mess up other things
Makes mouseevents set up selection stuff

- TODO: Discuss how to handle having events in scripts other
than event scritps
Fixes #5 clicking on hud element clicks on objects

- This means that selection happens on mousedown, not mouseup,
which is not always the expected behavior. Perhaps this is
better for allowing mouse drag though.