Fix command line devenv builds for MS VS 7.0 users. msdev is a command

  Fix command line devenv builds for MS VS 7.0 users.  msdev is a command
  that no longer exists, and we won't count on .mak files [although they
  are much faster if they exist, as there is no such concept as /norecurse
  in this newer release.]  We will use the existance of a converted
  Apache.sln (solution) file as proof of 7.0, there isn't another graceful
  way to check that I see.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@95084 13f79535-47bb-0310-9956-ffa450edef68