Adds database update when selecting an estimate

Clicking on an estimation card adds the estimate to the requirement and
updates the database.
Authors: dbeckwith, quan1992
Adds user field to requirement voting

Used to see if the user has already voted for the current requirement.
Still no way of telling what the current user is though...
Authors: dbeckwith, quan1992
Begins validating date for deadline

Validating user entered date for deadline, and making sure it is not in
the past. Not fully functional with errors in the save button being
enabled or not.

Authors: dbtrue, ammesonb
Merge branch 'team9dev' into validate-deadline
Finishes validating date for deadline

Fixed bugs with save button. Button now grays out and enables at
appropriate times.

Author: dbtrue
Formatting and comments

Fixing formatting and adding some comments.

Author: dbtrue
Merge pull request #45 from dbeckwith/team9dev

Merge team9dev into feature-store_estimate
Automatically select newly entered requirement

Selects new requirement in new game panel when the requirement is saved.

Authors: dbtrue, ammesonb
Reworks right panel GUI according to Marty

Also adds a feature to the game tree so that it automatically expands a
tree node when you select it, reduces the amount of clicking you need to
do.
Authors: dbeckwith, quan1992
Disables save button on attempt with invalid date

Previously save button was not disabled if deadline was valid when entered
but not when save is clicked.

Author: dbtrue, ammesonb
Adds User Email Validation

Checks the user's inputted email address for the correct format. If the
user inputted an incorrect format, throws an InvalidEmailException in
UserManager. Utilizes regex.

Author: Shockolate Ellychou
Merge pull request #48 from dbeckwith/validate-deadline

Validate deadline
More gitignores
Merge pull request #50 from dbeckwith/feature-store_estimate

Changes some GUI to match Marty's recommendations
Merge pull request #51 from dbeckwith/email_validation

Adds User Email Validation
Merge remote-tracking branch 'origin/team9dev' into endGame