Added client-side required fields checks. Also moved most JS calls from the form's HTML to within create_assignment.js. Most Prototype within create_assignment.js converted to jQuery.
Merge branch 'assignment-required' of https://github.com/arkon94/Markus into arkon94-assignment-required
Merge branch 'master' of git://github.com/MarkUsProject/Markus into assignment-required
Fix for undisabling submit button in Chrome. Disabled buttons show not-allowed or normal cursor instead of pointer (depends on the browser/OS, I guess).
Removed unnecessary required fields * indicators (from all 3 locales)
Merge branch 'assignment-required' of https://github.com/arkon94/Markus into arkon94-assignment-required
Added due_date to fr.yml
Replace symbol hash rockets with 1.9 syntax in ERB

This is a global search-and-replace that replaces the Ruby 1.8 symbol
key hash rocket `syntax to Ruby 1.9 syntax in ERB files.

Since this is a big change list, the style issues in the changed lines
are not being dealt with so that errors are minimized and code review
is easier. There is one exception though:

If the lines before the change have a good alignment of hash keys that
span multiple lines and the lines after the change do not (because the
change might alters the number of spaces needed for the alignment), then
the alignment is fixed, such that no new style issues are introduced. If
the alignment was not correct to begin with, then it is not fixed.

As a result, please ignore linter comments for this change.

Tested:
- rake test:units
- rake test:functionals
- rails s