[MEDIUM] added the "reqtarpit" and "reqitarpit" features

It is now possible to tarpit connections based on regex matches.
The tarpit timeout is equal to the contimeout. A 500 server error
response is faked, and the logs show the status flags as "PT" which
indicate the connection has been tarpitted.
diff --git a/include/common/regex.h b/include/common/regex.h
index c7f1c21..05eae6b 100644
--- a/include/common/regex.h
+++ b/include/common/regex.h
@@ -37,6 +37,7 @@
 #define ACT_REMOVE	2	/* remove the matching header */
 #define ACT_DENY	3	/* deny the request */
 #define ACT_PASS	4	/* pass this header without allowing or denying the request */
+#define ACT_TARPIT	5	/* tarpit the connection matching this request */
 
 struct hdr_exp {
     struct hdr_exp *next;