PowerShell : Emit output on timeout

Currently the powershell module will throw an error when the timeout is exceeded, dropping all of the output gathered from the process already. This should probably be changed so any available output from the process should be sent to puppet first and then an error thrown.

https://github.com/puppetlabs/puppetlabs-powershell/blob/master/lib/puppet_x/templates/init_ps.ps1#L474