Icons: new property icon-rotation
Icons: add icon-rotation to depend_property icon-image
Merge pull request #33 from plepe/icon-rotation

Icons: new property icon-rotation
Merge branch 'master' into symbol

Conflicts:
	doc/mapnik-2.0.md
	doc/mapnik-2.2.md
	doc/mapnik-3.0.md
	pgmapcss/mapnik/mapnik-2.0.mapcss
	pgmapcss/mapnik/mapnik-2.0.mapnik
	pgmapcss/mapnik/mapnik-2.2.mapcss
	pgmapcss/mapnik/mapnik-2.2.mapnik
	pgmapcss/mapnik/mapnik-3.0.mapcss
Symbol: add symbol-rotation