Update readme, add library.properties.

Author: tdicola

README.md

@@ -8,6 +8,11 @@ send/receive values.  For example a sensor device that sends sensor measurements
 to AIO and then enters deep power-saving sleep for a period is perfect to use
 with this library.
 
+An alternative is the [Adafruit MQTT library](https://github.com/adafruit/Adafruit_MQTT_Library) 
+which uses the MQTT protocol to talk to Adafruit IO.  This is good for devices
+that are always on and need to keep a connection alive to to be quickly notified
+of changes.
+
 Currently this library supports the send API to send a value to a feed and the
 receive/last API to get the latest value from a feed.
 

library.properties

@@ -0,0 +1,9 @@
+name=Adafruit IO Arduino
+version=1.0.0
+author=Adafruit
+maintainer=Adafruit <info@adafruit.com>
+sentence=Arduino library to access the Adafruit IO REST API.
+paragraph=Arduino library to access the Adafruit IO REST API using the CC3000, ESP8266/generic Client, or FONA hardware.
+category=Communication
+url=https://github.com/adafruit/Adafruit_IO_Arduino
+architectures=*