ENH: remove reliance on OpenFOAM etc/config.sh/functions file.

- similar functionality in etc/tools/ThirdPartyFunctions to improve
  the independence of ThirdParty while reducing clutter in the callers.

- add useGcc function for convenience
- mask seeing our own git-repo when building

STYLE: various items

- eliminate old user-editable configuration in files - now command-line only.
- use *_BUILD_DIR instead of *_BINARY_DIR for more clarity of the purpose
- drop use of '-q' option for wmakeCheckPwd (already has stderr redirect)
- drop checkVersion for makeParaView since it stopped working properly
  with newer paraview version

CONFIG: update list of versions

makeLLVM

@@ -46,21 +46,22 @@
 # NO USER-CONFIGURABLE SETTINGS WITHIN THIS FILE
 #------------------------------------------------------------------------------
 # Run from third-party directory only
-cd ${0%/*} && wmakeCheckPwd -q "$WM_THIRD_PARTY_DIR" 2>/dev/null || {
+cd ${0%/*} && wmakeCheckPwd "$WM_THIRD_PARTY_DIR" 2>/dev/null || {
     echo "Error (${0##*/}) : not located in \$WM_THIRD_PARTY_DIR"
     echo "    Check your OpenFOAM environment and installation"
     exit 1
 }
 . etc/tools/ThirdPartyFunctions
 #------------------------------------------------------------------------------
-# LLVM/Clang version from OpenFOAM etc/config.sh file
-WM_COMPILER_TYPE=ThirdParty       # ensure we get the correct compiler settings
-WM_COMPILER=Clang                 # force values for 'clang'
 
-. $WM_PROJECT_DIR/etc/config.sh/functions
-_foamSource $($WM_PROJECT_DIR/bin/foamEtcFile config.sh/compiler)
+[ "${WM_COMPILER#Clang}" = "$WM_COMPILER" ] && WM_COMPILER=Clang  # Force clang
+WM_COMPILER_TYPE=ThirdParty                # Ensure we get the correct settings
+
+# LLVM/Clang version from OpenFOAM etc/config.sh file:
+_foamEtc config.sh/compiler
 
 llvmPACKAGE=$clang_version
+
 #------------------------------------------------------------------------------
 usage() {
     exec 1>&2
@@ -80,7 +81,7 @@ USAGE
     exit 1
 }
 #-----------------------------------------------------------------------------
-# Ensure CMake gets the correct C/C++ compiler
+# Compiler settings for CMake/configure
 [ -n "$WM_CC" ]  && export CC="$WM_CC"
 [ -n "$WM_CXX" ] && export CXX="$WM_CXX"
 
@@ -88,13 +89,10 @@ USAGE
 while [ "$#" -gt 0 ]
 do
     case "$1" in
-    -h | -help)
-        usage
-        ;;
-    -gcc)
-        export CC=gcc    # use gcc/g++
-        export CXX=g++
-        ;;
+    '') ;;      # Ignore empty
+    -h | -help) usage   ;;
+    -gcc)       useGcc  ;;
+
     -cmake)
         [ "$#" -ge 2 ] || die "'$1' option requires an argument"
         CMAKE_PATH="${2%%/}"
@@ -119,12 +117,12 @@ installBASE=$WM_THIRD_PARTY_DIR/platforms/$WM_ARCH$WM_COMPILER_ARCH
 
 # Build LLVM (clang)
 #   LLVM_SOURCE_DIR : location of the original sources
-#   LLVM_BINARY_DIR : location of the build
+#   LLVM_BUILD_DIR  : location of the build
 #   LLVM_ARCH_PATH  : location of the installed program
 # - Strip any trailing '.src' from the proper names
 
 LLVM_SOURCE_DIR=$sourceBASE/$llvmPACKAGE
-LLVM_BINARY_DIR=$buildBASE/${llvmPACKAGE%%.src}
+LLVM_BUILD_DIR=$buildBASE/${llvmPACKAGE%%.src}
 LLVM_ARCH_PATH=$installBASE/${llvmPACKAGE%%.src}
 
 #
@@ -143,11 +141,12 @@ then
     echo
     (
         cd $LLVM_SOURCE_DIR || exit 1
+        export GIT_DIR=$PWD/.git # Mask seeing our own git-repo
         make distclean 2>/dev/null
 
-        rm -rf $LLVM_BINARY_DIR
-        mkdir -p $LLVM_BINARY_DIR
-        cd $LLVM_BINARY_DIR
+        rm -rf $LLVM_BUILD_DIR
+        mkdir -p $LLVM_BUILD_DIR
+        cd $LLVM_BUILD_DIR
 
         set -x
         $LLVM_SOURCE_DIR/configure \
@@ -171,10 +170,11 @@ else
     echo
     (
         cd $LLVM_SOURCE_DIR || exit 1
+        export GIT_DIR=$PWD/.git # Mask seeing our own git-repo
 
-        rm -rf $LLVM_BINARY_DIR
-        mkdir -p $LLVM_BINARY_DIR
-        cd $LLVM_BINARY_DIR
+        rm -rf $LLVM_BUILD_DIR
+        mkdir -p $LLVM_BUILD_DIR
+        cd $LLVM_BUILD_DIR
 
         cmake=$(findCMake)