Bump jerk requirement.

Jerk 1.1.18 changed the msg.source from a string to a Channel object so
that you can iterate through clients in a channel. Need to cast the
source to get the channel name.

package.json

@@ -14,7 +14,7 @@
   },
   "engines": { "node": ">=0.6.0" },
   "dependencies": {
-    "jerk": ">=1.1.16",
+    "jerk": ">=1.1.18",
     "tiny": ">=0.0.2",
     "coloured": ">=0.2.0",
     "log": ">=1.1.1",

plugins/tell.js

@@ -39,7 +39,7 @@ Tell.prototype.gotDb = function (incomingDb) {
 }
 var isChannel = function (source) {
 	// check source (# or & means it's a channel)
-	var first = source.substr(0, 1);
+	var first = String(source).substr(0, 1);
 	if ('#' === first || '&' === first) {
 		return true;
 	}
@@ -61,7 +61,7 @@ var tellHandler = function (msg) {
 		myInterface.uniqueId(),
 		{
 			recipient: tellNick,
-			source: msg.source,
+			source: String(msg.source),
 			msg: {
 				time: Date.now(),
 				sender: msg.user,
@@ -103,7 +103,7 @@ var activityHandler = function (msg, prompt) {
 	}
 	db.fetch({},
 		function (doc, key) {
-			if (doc.source == msg.source && doc.recipient == msg.user) {
+			if (doc.source == String(msg.source) && doc.recipient == msg.user) {
 				return true;
 			}
 		},