Move GetMimeTypeFromFileName() and related structure to Mayaqua

The structure (containing all mimetypes) occupies almost 700 lines, which are a lot.

This is just the beginning of the refactor plan.

src/Mayaqua/HTTP.h

@@ -0,0 +1,13 @@
+#ifndef HTTP_H
+#define HTTP_H
+
+// MIME type
+struct HTTP_MIME_TYPE
+{
+	char *Extension;
+	char *MimeType;
+};
+
+char *GetMimeTypeFromFileName(char *filename);
+
+#endif