fix pscommand error messaging

plugins/commands/ps/command.rb

@@ -91,7 +91,7 @@ module VagrantPlugins
         args << "-password" << ps_info[:password]
         result = Vagrant::Util::PowerShell.execute(script_path, *args)
         if result.exit_code != 0
-          raise Errors::PowershellError,
+          raise Errors::PowerShellError,
             script: script_path,
             stderr: result.stderr
         end
@@ -108,7 +108,7 @@ module VagrantPlugins
         args << "-hostname" << ps_info[:host]
         result = Vagrant::Util::PowerShell.execute(script_path, *args)
         if result.exit_code != 0
-          raise Errors::PowershellError,
+          raise Errors::PowerShellError,
             script: script_path,
             stderr: result.stderr
         end

plugins/commands/ps/errors.rb

@@ -2,17 +2,21 @@ module VagrantPlugins
   module CommandPS
     module Errors
       # A convenient superclass for all our errors.
-      class PSError < Vagrant::Errors::VagrantError
+      class PSCommandError < Vagrant::Errors::VagrantError
         error_namespace("vagrant_ps.errors")
       end
 
-      class HostUnsupported < PSError
+      class HostUnsupported < PSCommandError
         error_key(:host_unsupported)
       end
 
-      class PSRemotingUndetected < PSError
+      class PSRemotingUndetected < PSCommandError
         error_key(:ps_remoting_undetected)
       end
+
+      class PowerShellError < PSCommandError
+        error_key(:powershell_error)
+      end
     end
   end
 end

templates/locales/command_ps.yml

@@ -3,7 +3,7 @@ en:
     detecting: |-
       Detecting if a remote PowerShell connection can be made with the guest...
     reseting: |-
-      Reseting WinRM TrustedHosts to their original value.
+      Resetting WinRM TrustedHosts to their original value.
 
     errors:
       host_unsupported: |-
@@ -14,3 +14,14 @@ en:
         Unable to establish a remote PowerShell connection with the guest. 
         Check if the firewall rules on the guest allow connections to the 
         Windows remote management service.
+
+      powershell_error: |-
+        An error occurred while executing a PowerShell script. This error
+        is shown below. Please read the error message and see if this is
+        a configuration error with your system. If it is not, then please
+        report a bug.
+
+        Script: %{script}
+        Error:
+
+        %{stderr}