Added start of instructions menu and pause menu.
Continued working on menus, instructions screen in particular. Added
ability to clear the MessageLayer.
Merge branch 'develop' into feature/menu

Conflicts:
	SleepyScientist/SleepyScientist/Game1.cs
	SleepyScientist/SleepyScientist/SleepyScientist.csproj
Just an edit to the csproj because of image files.
Fixed checkout errors.
Merge branch 'develop' into feature/menu. Added a Menu object and moved
all Menu logic into that class.

Conflicts:
	SleepyScientist/SleepyScientist/Game1.cs
	SleepyScientist/SleepyScientist/SleepyScientist.csproj
Continued to modify menus. Changed resume to back and used a
state-prevstate system to handle that. Also added some of the new button images.
Moved menus to the Menu class.
Changed storage of menus from lists to dictionaries to facilitate ease of
access.
Updated menu arrangements.
Added TextHelper to help with drawing text.
Set up the TextHelper and renamed some image assets.
More slight changes.
Continued updating menus. Now have sound toggle and resume button in pause
menu.

Conflicts:
	SleepyScientist/SleepyScientist/SleepyScientist.csproj
Fleshed out instructions menu some.
Merged feature/menu
Asset name conflicts :(