individual comment un/release for mixed evaluation has been implemented

Instructors can now:
- "save changes" and release individual comments
- un/release all comments for an individual evaluatee
- un/release all comments for all members in a group
- un/release all comments for an event
fixed group event release statuses

I have modified the grade/comment release
code to also update the group event's grade and comment release
status. This is to correctly show the statuses on the evaluations
homepage.
implemented the feature to un/release individual comments in mixeval

- now users can un/release individual comments; so that inappropriate
comments can be hidden
- fixed the broken tests in the evaluation component test suite; some
were broken due to the change in data format made for the new feature
- moved un/releasing all grades and comments for an evaluatee or the
whole group buttons near the top of the detailed evaluation results
page. It is placed in a table format. This allows users to easily
release groups of grades and comments without having to navigate
through multiple accordions. The second reason is the user can now
easily see the release status of grades and comments for any students
in the group without the need to scroll through the results view.
modified simple evaluation's un/releasing comments mechanism

- the mechanism to un/release comments have been modified to have
the same structure as rubric and mixed evaluations. (eg. updates
last modified date)
- users now cannot release comments/grades before the event closes.
This is the same behaviour for the other evaluation types
- when un/releasing grades / comments for simple evaluations, the
group_event's reviewed/release statuses are also updated.
updated the auto_release mechanism for edit events

Now, if a user changes the auto release status of a event, the release
status of the submitted evaluations are automatically change. The only
exception is if the group event is already marked as reviewed; then the
release status are left untouched. I've also removed the messages alerting
the user that the event's result is auto_release since the system now
changes the release status automatically. Lastly, I fixed the checkboxes
for un/releasing individual comments for rubric and mixed evaluations from
showing up when the event has not ended (the "save changes" and "un/release"
buttons are already not visible when the event has not ended).