Merging with master

 - Changing from result method to get_latest_result because it an array
now.
 - Deletion of return statements
 - Trying to respect the 80 chars
Merge remote-tracking branch 'origin/master' into issue-798
Fix: ruby 1.8 not set by default anymore
Merge branch 'master' of github.com:benjaminvialle/Markus into update
Fix: array with ruby 1.9
Closes 997: Allow multiple files

 - Just adding of the attribute multiple
Closes #191: add unique index on DB level

 - adding of an index for annotation_categories
Merge pull request #1114 from GhiGt/issue-191

Closes #191: add unique index on DB level
Merge pull request #1101 from benjaminvialle/update

Fix: ruby 1.8 not set by default anymore
Merge pull request #1112 from benjaminvialle/FixTest

Fix: array with ruby 1.9
Closes #1115: link to repo_browser

 - adding a link
 - editing the i18n
 - deleting the css method background: inherit;
Deleting of my warning
Closes 1104: Indicate to the grader a post deadline submission

 - Adding a warning icon in submission/browse before the date
Correction of useless argument
Merge pull request #1118 from GhiGt/corrections-useless-attr

Correction of useless argument
Merge pull request #1117 from GhiGt/issue-1104

Closes #1104: indicate to the grader a post deadline submission
Merge pull request #1116 from GhiGt/issue-1115

Closes #1115: link to repo_browser
Closes #474: Move custom validations to lib

 - Application of the patch
Merge pull request #1119 from GhiGt/issue-474

Closes #474: move custom validations to lib

We put our custom validators in a library validation class and then use validates.
Merge pull request #1100 from GhiGt/issue-798

Closes #760 : TA cannot choose 'filter' attribute properly