0.9.13.50: Windows baby-steps

0.9.13.50: Windows baby-steps
  * Less sucky toplevel-init: use PARSE-NATIVE-NAMESTRING to deal with
    user-supplied init-file names, and refactor the logic between Posix
    and Windows.
  * New runtime option: --debug-environment, prints out the command line
    arguments and environment before anything fancy gets done to them.
    Good for debugging startup from Windows shortcuts, etc.
  * Less magic constants, more groveled stuff.
  * SB-WIN32::GET-FOLDER-PATH renamed to SB-WIN32::GET-FOLDER-PATHNAME,
    and it now returns pathnames instead of strings.
  * Add internal function SBCL-HOMEDIR-PATHNAME, and centralize the
    SBCL_HOME stuff there.
  * Still LESS_SHOUTING.
  * Move stuff-groveled-from-headers.lisp earlier in the build-order,
    so toplevel.lisp can use it.
  * No localtime_r and gmtime_r on Windows.