finalize multiple_login, change default menu of report to multiple login

fix download score in user_stat not working

remove junk from ealier merge

confusing merge

merge with dae

merge with dae again

modify user list creation into user list update

add download score as csv

add table sorter and combine user_stat and user_stat_max action into one view

shows scores only for submitted problems

add feature check maximum score in submission ranges available in the [result] admin menu. A user can enter a range of submissions id and the maximum score per each user,problem among the submission ranges will be reported (grafted from a9d427f3be11871c9948750e94ba5ae988f24eb7)

fixed form_tag bug in views

moved send mail code back to helper

sends mails by mail gem

renamed model Configuration to GraderConfiguration, renamed rhtml views to erb, fixed other small errors

sends mass emails

added default contest

fixed new users import bug when passwords contain extra spaces at the end

shows more login/contest info on result page

also shows users in all (without pagination)