Supports concurrent nbrplayer sessions

Uses python script to overcome webex/nbrplay restriction to run just a single nbrplay instance. The script uses Windows ability to create number of desktop objects, each desktop can run a single nbrplay instance.

Additional required updates:
- runUniqueDesktop.py - python script
- windows.workers.ini - to change the params.webexNbrplayerCmd assignment to:
params.webexNbrplayerCmd    						= "c:\Python27\python.exe c:\opt\kaltura\runUniqueDesktop.py C:\ProgramData\webex\WebEx\500\nbrplay.exe"

Test notes;
- Sanity run on all windows transcoding flows:
-- Webex
-- SmoothStreaming
-- WMV