fix error message when submission to closed problem

prevents submission language assignment when already specified

resize submissions.source field from "TEXT" to "MEDIUMTEXT"

- after submission, redirecto to edit_submission_path - add more info to submission status - fix bug #20 and #21

fix access right control bugs

fix allow admin to submit to any problem

add rejudge button

change find(:xxx) to correct syntax for rails 4

Change to better error message when the submitted file has illegal extension Solve issue #4

update problem stat to show all submissions change view to haml

saves submitted output, checks time outs; updated submission front-end flows

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)

added submission_status to store grading results, first page shows only unpassed problems.

added timestamp to source download git-svn-id: http://theory.cpe.ku.ac.th/grader/web/trunk@365 6386c4cd-e34a-4fa8-8920-d93eb39b512e

added problem identification from source filename git-svn-id: http://theory.cpe.ku.ac.th/grader/web/trunk@364 6386c4cd-e34a-4fa8-8920-d93eb39b512e

added language identification using file extension git-svn-id: http://theory.cpe.ku.ac.th/grader/web/trunk@363 6386c4cd-e34a-4fa8-8920-d93eb39b512e

[web] better ui for announcement and prob stat git-svn-id: http://theory.cpe.ku.ac.th/grader/web/trunk@195 6386c4cd-e34a-4fa8-8920-d93eb39b512e

[web] added support for output only problems git-svn-id: http://theory.cpe.ku.ac.th/grader/web/trunk@188 6386c4cd-e34a-4fa8-8920-d93eb39b512e

[web] add validations to test_request and submission git-svn-id: http://theory.cpe.ku.ac.th/grader/web/trunk@173 6386c4cd-e34a-4fa8-8920-d93eb39b512e

[web] fix problem availability bug git-svn-id: http://theory.cpe.ku.ac.th/grader/web/trunk@155 6386c4cd-e34a-4fa8-8920-d93eb39b512e