Moved DPD signatures into script specific directories.

- This caused us to lose signatures for POP3 and Bittorrent.  These will
   need discovered in the repository again when we add scripts
   for those analyzers.

scripts/base/protocols/http/__load__.bro

@@ -4,3 +4,5 @@
 @load ./file-ident
 @load ./file-hash
 @load ./file-extract
+
+@load-sigs ./dpd.sig

scripts/base/protocols/http/dpd.sig

@@ -0,0 +1,13 @@
+signature dpd_http_client {
+  ip-proto == tcp
+  payload /^[[:space:]]*(GET|HEAD|POST)[[:space:]]*/
+  tcp-state originator
+}
+
+signature dpd_http_server {
+  ip-proto == tcp
+  payload /^HTTP\/[0-9]/
+  tcp-state responder
+  requires-reverse-signature dpd_http_client
+  enable "http"
+}