Map Signs are not easy to click

[ethanmoffat]

In order to open a sign on a map, you must click on the lower-left square on the sign.

Preferably, a user would be able to click on any area of the sign graphic (right now it is only based on that one tile spec)

[ethanmoffat]

Possible implementation approach for this is to make the signs into their own "actor" type objects (like NPCRenderer and CharacterRenderer) that are able to test their clickable area as any pixel that is not a transparent background pixel.