Merge branch 'FrontEnd' into SubMaster/TestingLevel
Added Constants file

Added a constants.js file, where all assumed (hardly changing) elements
are stored in the form of arrays.
Added global functions file

Added globalFunctions.js file to house all global client-side functions
used throughout the system
Created session file

Session.js created -  a way to store user information after login
Merge branch 'FrontEnd' into SubMaster
Merge branch 'Controllers' of https://github.com/team-16/TimetablingSystem into Controllers
Merge branch 'Controllers' into SubMaster
Merge branch 'SubMaster' into FrontEnd