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.