add category icons (grey&white) in static/images folder
Merge branch 'dev-xiaoli'

* dev-xiaoli:
  add category icons (grey&white) in static/images folder

Conflicts:
	src/SocialNwk/Photographer/static/photo_load.js
add visualization css into site_stat.css
Merge pull request #42 from leituo56/sammie_visualization

add visualization css into site_stat.css