Merge pull request #18 from Olyol95/master

Subgroup1
Merge pull request #20 from Olyol95/master

Subgroup3
Finished appointment GUI modelling, created a textfield class capable of
displaying hints
Merge pull request #21 from Olyol95/Subgroup3

Subgroup3
Updated notes
Merge pull request #22 from Olyol95/master

Subgroup1
Merge pull request #23 from Olyol95/Subgroup1

Subgroup1
Merge pull request #25 from Olyol95/Subgroup2

Merge pull request #19 from Olyol95/master
Merge pull request #26 from Olyol95/master

Subgroup3
added basic command handling for main menu and exit button that had been
removed
Merge pull request #27 from Olyol95/Subgroup3

Subgroup3
Merge pull request #24 from Olyol95/master

Subgroup2