ENH: add 'subcommand' handling to wmake (#1693)

- initial split of wmake-related commands into "plumbing" and
  "porcelain" akin to how git handles things.

- wmakeBuildInfo (very low-level), now relocated to the wmake/scripts
  and accessible for the user as "wmake -build-info".

  This satisfies a long-standing desire to access build information
  in a fashion similar to the api/patch information.

CONFIG: avoid git information when building with a debian/ directory

- when a 'debian/' directory exists, there is a high probability that
  the '.git/' directory is from debian and not from OpenFOAM (ie,
  useless here). This corresponds to an implicit '-no-git', which has
  no effect when building from pristine sources.

ENH: wmakeCheckPwd becomes scripts/wmake-check-dir

- accessible for the user as "wmake -check-dir" and with 1 or 2
  directory names. A wmakeCheckPwd symlink left for compatibility.

wmake/wmakeLnIncludeAll

@@ -7,7 +7,7 @@
 #    \\/     M anipulation  |
 #------------------------------------------------------------------------------
 #     Copyright (C) 2011-2016 OpenFOAM Foundation
-#     Copyright (C) 2018 OpenCFD Ltd.
+#     Copyright (C) 2018-2020 OpenCFD Ltd.
 #------------------------------------------------------------------------------
 # License
 #     This file is part of OpenFOAM.
@@ -102,7 +102,7 @@ done
 # project directory: {applications,src} directories
 if [ "$#" -eq 0 ]
 then
-    if wmakeCheckPwd "$WM_PROJECT_DIR" 2>/dev/null
+    if wmake -check-dir "$WM_PROJECT_DIR" 2>/dev/null
     then
         set -- applications src
     else