add some C includes

Change-Id: I692d26e909240538685c10c1b347270db7359174
diff --git a/lib/IDS/DeReKoVecs/derekovecs-server.c b/lib/IDS/DeReKoVecs/derekovecs-server.c
index 5b23b03..6592bfa 100644
--- a/lib/IDS/DeReKoVecs/derekovecs-server.c
+++ b/lib/IDS/DeReKoVecs/derekovecs-server.c
@@ -5,6 +5,9 @@
 #include <stdlib.h>
 #include <string.h>
 #include <sys/mman.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <perl.h>
 
 #define max_size 2000
 #define max_w 50