Separate NAZARA_API into multiple defines (one per module)

To fix inter-module dependency


Former-commit-id: 64704f020e0af22e529d38527323ba977187d4d0

include/Nazara/Core/MemoryManager.hpp

@@ -11,7 +11,7 @@
 #include <cstdio>
 #include <cstring>
 
-class NAZARA_API NzMemoryManager
+class NAZARA_CORE_API NzMemoryManager
 {
 	public:
 		static void* Allocate(std::size_t size, bool multi = false, const char* file = nullptr, unsigned int line = 0);