Implement first pass on rapid dead path detection, and increment version to 1.1.3 (dev)

node/Packet.hpp

@@ -655,32 +655,11 @@ public:
 
 		/**
 		 * ECHO request (a.k.a. ping):
-		 *   <[1] 8-bit purpose of echo request>
-		 *   <[...] additional arbitrary payload>
+		 *   <[...] arbitrary payload>
 		 *
 		 * This generates OK with a copy of the transmitted payload. No ERROR
 		 * is generated. Response to ECHO requests is optional and ECHO may be
 		 * ignored if a node detects a possible flood.
-		 *
-		 * An empty payload is permitted. This is used in some versions for
-		 * path checking and validation. If a payload is present it must
-		 * follow the above format, though the recipient does not have to check
-		 * this. It can simply echo it back.
-		 *
-		 * Echo purpose codes:
-		 *   0x00 - User ECHO request
-		 *   0x01 - Dead path detection
-		 *
-		 * Support for fragmented echo packets is optional and their use is not
-		 * recommended.
-		 *
-		 * Dead path detection is performed by sending ECHOs with the same random
-		 * payload to the best (or every) direct path and then once indirectly
-		 * (such as via a root server). When an OK is received echoing back this
-		 * test payload, all paths that have not yet received this OK are cancelled
-		 * or re-tested. This can be done after a short period of inactivity to
-		 * detect and automatically cancel dead paths without requiring any
-		 * special logic (other than support for ECHO) at the remote end.
 		 */
 		VERB_ECHO = 8,