Change ItemID to Guid type
Merge pull request #6 from vhil/master

Change ItemID to Guid type
Merge branch 'master' into develop
Merge branch 'develop' into feature/Mvc

Conflicts:
	Fortis/Model/ItemFactory.cs
	Fortis/Model/Spawn.cs
Fixed issues from merge from develop,
Refactored unit tests to use Guids