- Implement CMD /D, /Q, and /R switches

- Implement CMD /D, /Q, and /R switches
- Do %envvar% expansions in CMD /C or /K commands
- Make SETLOCAL recognize ENABLEEXTENSIONS and DISABLEEXTENSIONS, although it doesn't do anything yet
- Make VERIFY set the errorlevel (documented in SETLOCAL /?). Also make it recognize when ON/OFF is followed by space
- Make ECHOSERR actually print to stderr, not stdout
- Make echoed display of ( ... ) blocks look nicer (Bug 4022)
- Fix some other minor display bugs

svn path=/trunk/; revision=40244