CONFIG: improve prefix matching for system libraries (#1607)

- missed detection of system libraries when installed with multiarch
  paths like /usr/lib/x86_64-linux-gnu

CONFIG: improve handling of group/user config files (#928)

- changed bashrc handling of FOAM_CONFIG_NOUSER to use
  FOAM_CONFIG_MODE instead. Propagate into foamEtcFile to make this
  a stickier control.

  This change allows better control, but also enables cluster
  installations to define their own value within the OpenFOAM prefs.sh
  file to prevent users accidentally mis-configuring things if
  necessary.

- remove undocumented handling of an (a)ll mode in foamEtcFile to
  avoid potential pitfalls.

- add support for FOAM_CONFIG_ETC handling.
  This allows injection of an extra search layer when finding
  project etc files

ENH: improvements to foamConfigurePaths (#928)

- handle FOAM_CONFIG_ETC implicitly, or explicitly with the new
  -etc option.

STYLE: more explicit wording in foamConfigurePaths usage (#1602)

- document that an absolute path (eg, -scotch-path) overrides/ignores
  the equivalent ThirdParty setting (eg, -scotch)

- longer options -system-compiler and -third-compiler for -system
  and -third, respectively. Clearer as to their purpose.

- adjust the location sanity check to look for META-INFO directory.

bin/foamLog

@@ -7,6 +7,7 @@
 #    \\/     M anipulation  |
 #-------------------------------------------------------------------------------
 #     Copyright (C) 2011-2016 OpenFOAM Foundation
+#     Copyright (C) 2020 OpenCFD Ltd.
 #------------------------------------------------------------------------------
 # License
 #     This file is part of OpenFOAM.
@@ -38,8 +39,6 @@
 #------------------------------------------------------------------------------
 Script="${0##*/}"
 toolsDir="${0%/*}/tools"
-groupDir="${WM_PROJECT_SITE:-${WM_PROJECT_DIR:-<unknown>}/site}"
-userDir="$HOME/.OpenFOAM"
 
 usage() {
     exec 1>&2
@@ -91,13 +90,9 @@ cat <<HELP
     The value taken will be the first (non-space)word after this column.
 
     The database ($Script.db) will taken from these locations:
-        .
-        $userDir/$FOAM_API/
-        $userDir/
-        $groupDir/$FOAM_API/etc/
-        $groupDir/etc/
-        $WM_PROJECT_DIR/etc/
-        $toolsDir
+      ./
+$(foamEtcFile -list | sed -e 's#^#      #')
+      $toolsDir
 
     option -quiet : suppresses the default information and only prints the
     extracted variables.