REORG: proto_htx: Move HTX analyzers & co to http_ana.{c,h} files

The old module proto_http does not exist anymore. All code dedicated to the HTTP
analysis is now grouped in the file proto_htx.c. So, to finish the polishing
after removing the legacy HTTP code, proto_htx.{c,h} files have been moved in
http_ana.{c,h} files.

In addition, all HTX analyzers and related functions prefixed with "htx_" have
been renamed to start with "http_" instead.
diff --git a/include/types/stream.h b/include/types/stream.h
index 114b70a..c889345 100644
--- a/include/types/stream.h
+++ b/include/types/stream.h
@@ -35,7 +35,7 @@
 #include <types/filters.h>
 #include <types/hlua.h>
 #include <types/obj_type.h>
-#include <types/proto_http.h>
+#include <types/http_ana.h>
 #include <types/proxy.h>
 #include <types/queue.h>
 #include <types/server.h>