- unknown options or missing option values now emit a shorter message
  without the entire usage. This makes it easier to identify the errors
  and is better aligned with the behaviour of GNU system tools.

  ====
     $ simpleFoam -case
     Using: OpenFOAM-plus (see www.OpenFOAM.com)
     Build: plus-01234

     Error: option '-case' requires an argument

     See 'simpleFoam -help' for usage
  ====

- provide for reduced (-help) and full (-help-full) usage information.
  In many cases the reduced usage provided sufficient and easier
  to find the information.

- make -srcDoc an alias for -doc-source

- no warnings about option aliases for future dates.

Added a 'deprecated' comment and recommendation to use 'foamLog'

- alternative to WM_PROJECT_INST_DIR/site for systems with locked down
  installation paths (eg, when packaged as RPM or deb)

  When "$WM_PROJECT_SITE" is defined, it is used in favour of
  "$WM_PROJECT_INST_DIR/site"

This reverts commit c5bea524.

This reverts commit 2e1e671d.

- improves flexibility and allows more consistent long options

- drop reference to license directory
- check -help before checking directories

- search for foamLog.db is more consistent with foamEtcFile
    $HOME/.OpenFOAM/$WM_PROJECT_VERSION
    $HOME/.OpenFOAM
    $WM_PROJECT_INST_DIR/site/$WM_PROJECT_VERSION
    $WM_PROJECT_INST_DIR/site
    $WM_PROJECT_DIR/etc
    $PROGDIR/tools