Added up/down arrows for changing speed.
Merge branch 'develop' of https://github.com/DAWacker/SleepyScientist into develop
Moved back button in instructions screen.
Merge branch 'feature/AI' of github.com:DAWacker/SleepyScientist into develop

Conflicts:
	SleepyScientist/SleepyScientist/Game1.cs