Fix encoding errors on Windows guests (fixes: #156)

On Windows guests the default encoding will be set to whatever
default legacy encoding, not utf-8. This issue isn't apparent on English locale
Windows guests, as there the encodings (ISO-8859-1, utf-8) happen to coincide.

However, on e.g. German Windows guests this will cause an encoding error when
reading any output from there.

This patch ensures that the proper encoding is set on every command.

plugins/connection/libvirt_qemu.py

@@ -160,6 +160,10 @@ def exec_command(self, cmd, in_data=None, sudoable=True):
             # prompt that will not occur
             sudoable = False
 
+            # Make sure our first command is to set the console encoding to
+            # utf-8, this must be done via chcp to get utf-8 (65001)
+            cmd = ' '.join(["chcp.com", "65001", self._shell._SHELL_REDIRECT_ALLNULL, self._shell._SHELL_AND, cmd])
+
             # Generate powershell commands
             cmd_args_list = self._shell._encode_script(cmd, as_list=True, strict_mode=False, preserve_rc=False)