Added win_argv_escape.
Added win_argv_escape.

This function is not needed unless we have to pass an argument
to a command under Windows. In this case we should escape with
both win_argv_escape and cmd_exe_escape.

git-svn-id: 0da8f21dee8ca9acab225f08fca9f7eff6b6e134@63 4622ca98-d053-0410-b680-d1345939a8d7

mit-nlp/mitlm,mit-nlp/mitlm,mit-nlp/mitlm