When the winrm communicator executes a command in an elevated shell,
this patch causes it to escape double quotes.
This is necessary as the first line in the file that it produces and
then executes it puts the command into a variable called command that
is delimited by double quotes.
Command failures include the stdout and stderr in the error message just like the SSH communicator.
Its now possible to specify only an error_class and have that use the correct error_key by default.
Elevated command line is now rendered to a script which is uploaded to the guest and executed. This allows the command line itself to be less than 100 chars to start the script and any user commands are puts into the script which has unlimited* length.
*nix commands are now filtered out instead of being sent to the guest. This means the command_alias PowerShell script is no longer needed.
Moved the PowerShell exit code helper to the WinRM shell and changed it to always return an exit code.
