Merge pull request #58 from calin-iorgulescu/master

Security fixes for the services and the GWT interface. Minor other enhancements.
vmchecker: SubmitOnly feature

Sometimes we want to use VMchecker only as a submit and save system.

Signed-off-by: Lucian Cojocar <cojocar@gmail.com>
Merge pull request #59 from cojocar/submitonly-feature

vmchecker: SubmitOnly feature
ShowGradesBeforeDeadline: new feature

Enabling this switch will show the grades to everybody before the
deadline.

Signed-off-by: Lucian Cojocar <cojocar@gmail.com>
Merge pull request #60 from cojocar/show-grades-before-deadline-feature

ShowGradesBeforeDeadline: new feature