improved the display position of 'detail_card_info'
* indicator/templates/indicator/SheetDefault.html:
  destroy 'qtip' when close card

* added new app 'apps/sfaccount'
* implemented 'signup' and 'activate' functions
* implemented async sending activation mail
  (using 'django-celery' and 'redis')
* moved 'registration/*' templates to 'sfaccount/templates'

* implemented 'password_change' function:
  o password_change
  o password_change_done
* implemented 'password_reset' function
  o password_reset
  o password_reset_done
  o password_reset_confirm
  o password_reset_complete
  o re-write 'sfaccount.fomrs.SFPasswordResetForm'
  o re-write 'sfaccount.views.password_reset_view'
* improved 'sfaccount.functional' send mail functions
  o to send 'multipart' mail

* added 'README.txt'

* added app 'apps/recommend':
  for comparing with the SCI papers and then recommending
  most related papers for user.