Streaming: Support offline signatures (proposal 123)

Don't send FROM in RESET, not required since 0.9.20
Send RESET when SYN signature verification fails
Use cached buffers for signature verification
Move setOptionalFrom() from Packet to PacketLocal
Always verify packets with signatures, even if not required
AIOOBE checks
cleanups, log tweaks

router/java/src/net/i2p/router/RouterVersion.java

@@ -18,7 +18,7 @@ public class RouterVersion {
     /** deprecated */
     public final static String ID = "Monotone";
     public final static String VERSION = CoreVersion.VERSION;
-    public final static long BUILD = 4;
+    public final static long BUILD = 5;
 
     /** for example "-test" */
     public final static String EXTRA = "";