Hue Group bug fixes

* Fixed a bug that caused the plugin to crash if there were any Hue
groups registered with the Hue hub.
* Fixed a bug that prevented Hue Group devices from being loaded when
the "Reload Hue Device List" plugin menu option was selected within the
Indigo client.
Generic ZigBee Lights. Group Device Bug Fix

  -- Added support for generic ZigBee lights such as the GE Link.
  -- Fixed a bug that caused the plugin to crash if an alert action was
taken on a Hue Group device.