Merge pull request #41 from leituo56/Dev_TuoLei

Dev tuo lei
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
add icon yellow sets
Merge pull request #43 from leituo56/dev-xiaoli

add icon yellow sets
edit stat_visualization
Merge pull request #44 from leituo56/sammie_visualization

edit stat_visualization
add xiaoli's icons to explore page
Merge pull request #45 from leituo56/dev_jenn2

add xiaoli's icons to explore page
drop down menu, fix icon link
Merge pull request #46 from leituo56/dev-xiaoli

drop down menu, fix icon link
find_friend function finish
Merge pull request #47 from leituo56/dev-xiaoli

find_friend function finish
edit files for visualization
Merge pull request #48 from leituo56/sammie_visualization

edit files for visualization
update files only
Merge pull request #49 from leituo56/sammie_visualization

update files only
add icons to filter bar & change when hover (active not done)