Hiding old test code. Adding guids to zip-files.
Formatting, renaming.
Added GUID-table for all existing resources.
Added GUID-mapping for loaded resource.

Checks if GUID already exist and prevents loading of duplicated files. Thread safety added.
Do not use weak_ptr when using resources.
Merge remote-tracking branch 'origin/master' into guid
Changed function name.
Fixed probable wrong unlock-step.
Merge branch 'master' into Demo

Conflicts:
	GameEngine/Demo/Source/Level.cpp