Reposition infobox if offscreen
Reposition infobox if offscreen

Fixes #516

alphalambda/codeworld,google/codeworld,three/codeworld,pranjaltale16/codeworld,tgdavies/codeworld,tgdavies/codeworld,parvmor/codeworld,pranjaltale16/codeworld,three/codeworld,parvmor/codeworld,alphalambda/codeworld,pranjaltale16/codeworld,three/codeworld,venkat24/codeworld,venkat24/codeworld,alphalambda/codeworld,parvmor/codeworld,google/codeworld,tgdavies/codeworld,venkat24/codeworld,google/codeworld