love.graphics.draw's should default to rotating around the center, not top-left corner
I'm creating this issue because I believe that the most usual case when someone is drawing a rotated image is doing so around its center. Rotating around the top-left corner is something that happens very rarely, however it is the default behavior.
I hereby propose that on the next version of LÖVE, ox and oy default to "half-width" and "half-height" respectively. Reverting to the previous behaviour would be as simple as passing 0,0.
Probably it would help to have a getDimensions method available in all drawables first (