Added a ToVector extension to Direction
Modified player to handle spell cooldowns
Minor changes
Changed Spell to a bare interface
Minor cosmetic fixes mostly
Changed to singleton and moved in the correct namespace
Added a new spell and a Spellbook class
Cosmetic fixes
Merge remote-tracking branch 'origin/development' into development

Conflicts:
	flaming-octo-meme/flaming-octo-meme/Entities/Player.cs
	flaming-octo-meme/flaming-octo-meme/Entities/Projectile.cs
	flaming-octo-meme/flaming-octo-meme/Game1.cs
	flaming-octo-meme/flaming-octo-meme/Spells/Firebolt.cs
	flaming-octo-meme/flaming-octo-meme/Spells/FireboltProjectile.cs