normalizing line breaks in sig-alternate.cls
pruning, re-arranging, typos in sections 1. and 2.
Merge branch 'master' of github.com:jodaiber/spotlight-www2013

Conflicts:
	doc/WWW2013.tex
Merge branch 'master' of github.com:jodaiber/spotlight-www2013

Conflicts:
	doc/WWW2013.tex