Merge pull request #41 from RenchuSong/master

join group
Merge pull request #42 from RenchuSong/master

update process
fix bug: group creator can exit the group in "find group" page
ui optimization
ui optimization
db dump
main_nav module and user_home_nav module
integrate profile, profile edit, last posts, messages view into user home page
Update database model
fix bugs: main nav
add counter model
update database model | add post view counter
add delete confirm dialog
fix bugs: delete topic action should delete counter too
apply join
Merge https://github.com/Raysmond/FDUGroup
join group censorship