included the ability to comment questions and answers

A form has been created to assist the users in posting comments.
Currently, the comments are all displayed under their respective
post (ques/answer) within an area that is indented from the left.
Added test cases for getting and creating comments

I've found a bug with some of the test cases where the expected
404 is returned but not for the reason we expected. It was
returning 404 for an invalid url instead of the expeced invalid
id. The appropriate changes have been made. Additionally, some
queries are added to check for the ids' validity (until a better
solution is found)

I've also added permissions for comments for the different user
types.
Implemented the ability to edit comments

Firstly, I have modified the models for comments to include a hybrid
field for the content of the comment. This allows us to read the content
without the need to dig too deep. Secondly, users can now edit the
comments that they have access to.
Modified creating/editing comments interface

Firstly, I fixed the answer model that was trying to query Questions,
which doesn't exist. Instead it is PostsForQuestions.

I have also modified the comments form to display the question and
answer the comment relates to. Also I have modified the controller
to redirects to an appropriate page after editing a question and a
comment
Implemented user creation

I've created a form to manually create users. A link has also been
added to the navigation bar (as long as the user has the permission
to create users). A new directive has been created to check the
password and "verifyPassword" matches. Furthermore, the username
and display name is checked to be unique before the user is created.
Implemented user edit / edit profile

Currently, usrs that have the permissions to manage users can edit
other users' username and user types. Other users that can edit
users but not mange users cannot modify those two fields. Moreover,
currently, no password reset mechanism has been implemented on the
administrator/instructor side. Users themselves can however change
their password in edit profile.

- need to implement reset password
- need to create a user list page / link to edit user
	- currently the only way to access is /user/:id/edit