Restructure code

PubSubClient/CHANGES.txt

@@ -0,0 +1,29 @@
+1.6
+    * Added the ability to publish a retained message
+
+1.5
+    * Added default constructor
+    * Fixed compile error when used with arduino-0021 or later
+
+1.4
+    * Fixed connection lost handling
+
+1.3
+    * Fixed packet reading bug in PubSubClient.readPacket
+
+1.2
+    * Fixed compile error when used with arduino-0016 or later
+
+
+1.1
+    * Reduced size of library
+    * Added support for Will messages
+    * Clarified licensing - see LICENSE.txt
+
+
+1.0
+    * Only Quality of Service (QOS) 0 messaging is supported
+    * The maximum message size, including header, is 128 bytes
+    * The keepalive interval is set to 30 seconds
+    * No support for Will messages
+