Adding missing hold call/resume call functions

* Version 1.5.28:
* Date: 22nd Aug 2014
* Compatible with Spokes SDK version(s): 3.x
* Tested with Hub version: 3.0.50718.1966
* Changed by: Lewis Collins
*   Changes:
*     - Adding missing hold call/resume call functions
*
* Version 1.5.28:
* Date: 19th Aug 2014
* Compatible with Spokes SDK version(s): 3.x
* Tested with Hub version: 3.0.50718.1966
* Changed by: Lewis Collins
*   Changes:
*     - Fixed error in the initial docked/undocked state detection.