STYLE: emit warning about using deprecated "~OpenFOAM" expansion

- Within strings it is preferable to use the "<etc>" instead.
  Most use cases for the old "~OpenFOAM" expansion have been obsoleted
  by the #includeEtc directive.

applications/test/etcFiles/Test-etcFiles.C

@@ -69,7 +69,7 @@ int main(int argc, char *argv[])
     argList::addNote
     (
         "Locate user/group/other file with semantics similar to the "
-        "~OpenFOAM/fileName expansion."
+        "<etc>/fileName expansion."
     );
 
     argList args(argc, argv, false, true);

bin/foamCopySettings

@@ -33,8 +33,8 @@
 #     - requires rsync
 #
 # Note
-#     The foamCopySettings.rc (found with the ~OpenFOAM expansion) can be used
-#     to add any custom rsync options.
+#     The foamCopySettings.rc (found via foamEtcFile) can be used to add any
+#     custom rsync options.
 #------------------------------------------------------------------------------
 Script=${0##*/}
 
@@ -51,8 +51,8 @@ Usage: $Script srcDir dstDir
     - requires rsync
 
 Note
-    The $Script.rc (found via the ~OpenFOAM expansion - see foamEtcFile)
-    can be used to add any custom rsync options.
+    The $Script.rc (found via foamEtcFile) can be used to add any
+    custom rsync options.
 
 USAGE
     exit 1

src/OpenFOAM/db/dynamicLibrary/dynamicCode/dynamicCode.C

@@ -162,7 +162,7 @@ bool Foam::dynamicCode::resolveTemplates
             }
         }
 
-        // Not found - fallback to ~OpenFOAM expansion
+        // Not found - fallback to <etc> expansion
         if (file.empty())
         {
             file = findEtcFile(codeTemplateDirName/templateName);
@@ -423,7 +423,7 @@ bool Foam::dynamicCode::copyOrCreateFiles(const bool verbose) const
             << "Could not find the code template(s): "
             << badFiles << nl
             << "Under the $" << codeTemplateEnvName
-            << " directory or via via the ~OpenFOAM/"
+            << " directory or via via the <etc>/"
             << codeTemplateDirName << " expansion"
             << exit(FatalError);
     }

src/OpenFOAM/global/argList/argList.H

@@ -76,7 +76,7 @@ Description
 Note
     - The document browser used is defined by the \b FOAM_DOC_BROWSER
       environment variable or the <tt>Documentation/docBrowser</tt> entry
-      in the <tt>~OpenFOAM/controlDict</tt> file.
+      in the <tt>\<etc\>/controlDict</tt> file.
       The \%f token is used as a placeholder for the file name.
     - The valid (mandatory) arguments can be adjusted
       via the addArgument static method instead of directly

src/OpenFOAM/primitives/strings/stringOps/stringOps.C

@@ -26,6 +26,7 @@ License
 #include "stringOps.H"
 #include "typeInfo.H"
 #include "etcFiles.H"
+#include "Pstream.H"
 #include "StringStream.H"
 #include "OSstream.H"
 #include "OSspecific.H"
@@ -92,8 +93,8 @@ static void expandLeadingTag(std::string& s, const char b, const char e)
 
 // Expand a leading tilde
 //   ~/        => home directory
-//   ~OpenFOAM => user/group/other OpenFOAM directory
 //   ~user     => home directory for specified user
+//   Deprecated ~OpenFOAM => <etc> instead
 static void expandLeadingTilde(std::string& s)
 {
     if (s[0] != '~')
@@ -121,6 +122,24 @@ static void expandLeadingTilde(std::string& s)
 
     if (user == "OpenFOAM")
     {
+        // Compat Warning
+        const int version(1806);
+
+        // Single warning (on master) with guard to avoid Pstream::master()
+        // when Pstream has not yet been initialized
+        if (Pstream::parRun() ? Pstream::master() : true)
+        {
+            std::cerr
+                << nl
+                << "--> FOAM Warning :" << nl
+                << "    Found [v" << version << "] '"
+                << "~OpenFOAM" << "' string expansion instead of '"
+                << "<etc>" << "' in string\n\"" << s << "\"\n" << nl
+                << std::endl;
+
+            error::warnAboutAge("expansion", version);
+        }
+
         s = findEtcFile(file);
     }
     else

src/OpenFOAM/primitives/strings/stringOps/stringOps.H

@@ -228,7 +228,6 @@ namespace stringOps
     //  -# tilde expansion
     //    - leading "~/" : home directory
     //    - leading "~user" : home directory for specified user
-    //    - leading "~OpenFOAM" : user/group/other OpenFOAM directory
     //
     //  Supports default and alternative values as per the POSIX shell.
     //  \code
@@ -245,6 +244,9 @@ namespace stringOps
     //  - Malformed entries (eg, brace mismatch, sigil followed by bad chars)
     //  are left as is.
     //
+    //  \note Deprecated(2018-11) Use "<etc>" instead of the rarely used
+    //      "~OpenFOAM" expansion
+    //
     //  \sa
     //  Foam::findEtcFile
     string expand
@@ -268,7 +270,6 @@ namespace stringOps
     //  -# tilde expansion
     //    - leading "~/" : home directory
     //    - leading "~user" : home directory for specified user
-    //    - leading "~OpenFOAM" : user/group/other OpenFOAM directory
     //
     //  Supports default and alternative values as per the POSIX shell.
     //  \code
@@ -285,6 +286,9 @@ namespace stringOps
     //  - Malformed entries (eg, brace mismatch, sigil followed by bad chars)
     //  are left as is.
     //
+    //  \note Deprecated(2018-11) Use "<etc>" instead of the rarely used
+    //      "~OpenFOAM" expansion
+    //
     //  \sa
     //  Foam::findEtcFile
     void inplaceExpand