Renamed ClearPrintQueues.ps1 script

I did this to reflect the system for which it was written for, that
being Windows Server 2008 R2. There is a difference between what is
needed for a script to run on 2008 and 2008 R2.
Renamed ClearPrintQueues again

After some testing, there is no difference in how the
ClearPrintQueues scrip runs on Server 2008 and 2008 R2.
A commit
Updated README.md