Separate NAZARA_API into multiple defines (one per module)

To fix inter-module dependency


Former-commit-id: 64704f020e0af22e529d38527323ba977187d4d0

include/Nazara/Core/LockGuard.hpp

@@ -11,7 +11,7 @@
 
 class NzMutex;
 
-class NAZARA_API NzLockGuard
+class NAZARA_CORE_API NzLockGuard
 {
 	public:
 		NzLockGuard(NzMutex& mutex);