Moved get_libdir function to its own file.

server/core/gwdirs.c

@@ -0,0 +1,10 @@
+#include <gwdirs.h>
+
+/**
+ * Get the directory with all the modules.
+ * @return The module directory
+ */
+char* get_libdir()
+{
+    return libdir?libdir:(char*)default_libdir;
+}