Enable deprecated prototypes when compiling deprecated functions.
Some integer conversion fixes.

lib/zip_add_dir.c

diff --git a/lib/zip_add_dir.c b/lib/zip_add_dir.c
index 84834b5..060ef03 100644
--- a/lib/zip_add_dir.c
+++ b/lib/zip_add_dir.c
@@ -36,6 +36,7 @@
 #include <stdlib.h>
 #include <string.h>
 
+#define _ZIP_COMPILING_DEPRECATED
 #include "zipint.h"