Web-app: reduced logo image size
Web-app: implemented 'make excuse' functionality
Web-app: added datepickers to "take attendance" form
Web-app: Added comment to attendance threshold page
Web-app: changed login button color
Web-app: improved timepicker style
Web-app: Changed radio inputs to use horizontal mode
Web-app: added notifications about new student excuses
Android: allow lecturer to view student excuses
Web-app: fixed field containers when creating group
Web-app: term -> semester
Web-app: removed unnecessary drop-down options
Web-app: ordered SQL query results
Web-app: fixed php warning
Web-app: redirect to correct form