Changelog of PHP SPBus API for Schleifenbauer PDUs
(c) Schleifenbauer Holding BV 2008..2015

1.60:
    * Implemented try-retry capabilities to increase the reliability. 
      This means that the api will (re-)establish its connections automatically.
      It further means that multiple devices can (simultaniously) make contact.
    * Implemented the capability to read large blocks of data. This way several 
      (measurement) values from the same register can be read at once, rather than 
      having to collect each several messages. 
    * Implemented a function to test the status of the ringbuffer of a hPDU with 
      firmware version larger than 2.36.
    * Implemented a logfunction which pushes all messages into a logfile.
    * Errors are caught and no longer forwarded to the output.
    * Fixed the firmware upgrade function.
    * Large code revision: by re-using code the class.spbus.php was significantly 
      reduced in size.
    * Added some examples for the new capabilities.

1.52:
    * Fixed bug in setRC4Key() which prevented the use of keys other
      than the default key.

1.50:
    * Fixed bug which caused incorrect reading of SPDM 3-byte integers
      (like kWh totals) when in a certain range.
    * Fixed filename for POST action in HTML form of all examples.