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.

META-INFO/README.md

@@ -1,59 +1,60 @@
 # META-INFO
 
-Meta-information is for OpenFOAM internal use only.
-
-Do not rely on any files or any file contents in this directory,
-or even the existence of this directory.
+Meta-information is generally for OpenFOAM internal use only.
 
 The format, content and meaning may be changed at anytime without
-notice.
+notice. If any of these are changed, these are some of places that
+will need to be updated accordingly:
 
-The information is provided here for internal documentation purposes.
+  - bin/foamEtcFile
+  - bin/tools/foamConfigurePaths
+  - bin/tools/foamPackRelease
+  - etc/openfoam
+  - wmake/scripts/wmake-build-info
 
 ## api-info
 
 This file and its contents are to be tracked by git.
 
-- File content (api) generated by wmakeBuildInfo from OPENFOAM define
-  in `wmake/rules/General/general`
-
+- File content (api) generated by `wmake -build-info` from the
+  `OPENFOAM` define in `wmake/rules/General/general`
 - File content (patch) is manually generated content.
 
 
 ## build-info
 
-This file is *never* to be tracked by git, but may be present in shipped
-source archives.
+This file is ***never*** to be tracked by git, but may be present in
+shipped source archives.
 
-- File content (branch, build) generated by wmakeBuildInfo from git
-  information and cached from previous wmake (api)
+- File content (branch, build) generated by `wmake -build-info` from
+  git information and cached from previous wmake (api)
 
 
 ## Content types
 
 ### api
 
+Format: `date +%y%m`
+
 - 4-digit year-month (YYMM) integer corresponding to the major
   release or in unusual cases an intermediate release.
-
-- Format is year-month, as per `date +%y%m`.
-  Eg, `1712` for the Dec-2017 release.
+  Example, `1712` for the Dec-2017 release.
 
 
 ### patch
 
+Format: `date +%y%m%d`
+
 - 6-digit year-month-day (YYMMDD) integer corresponding to a patch-level
   for the given **released** API.
-
-- Format is year-month-day, as per `date +%y%m%d`.
-
-- The first release can have a patch value of `0` (unpatched = just
-  released) or a patch value corresponding to the release date.
+- The first release can have a patch value of `0` or `1` which
+  indicates that it is unpatched or just released. Alternatively
+  it can have a patch value corresponding to the release date.
 
 The patch value is only meaningful together with the api value.
 However, for *development* branches, the patch level should not be
-ascribed much meaning -- it can be `0` or have a value corresponding
-to the last merge with a *maintenance* (*eg*, `master`) branch.
+ascribed too much meaning, but will often correspond to the last
+merge with a *maintenance* (*eg*, `master`) branch.
 
 
 ## Flow of information
@@ -70,9 +71,9 @@ distributions to have a record of the same information.
 | build     | git                       | build-info |
 
 
-The command `wmakeBuildInfo -check` is used to determine if
+The command `wmake -build-info -check` is used to determine if
 the saved information needs synchronization. The command
-`wmakeBuildInfo -update` preforms the synchronitzation.
+`wmake -build-info -update` performs the synchronization.
 
 
 ## Notes
@@ -82,4 +83,4 @@ contains more permanent information, whereas the `build-info` is more
 transient in nature.
 
 ----
-2019-01-23
+2020-05-05