ENH: use HashTable for mapping codeStream entries

- write intermediate code to _SHA1 directories
- add Test-codeStream

src/OpenFOAM/db/dictionary/functionEntries/codeStream/codeStream.H

@@ -29,11 +29,12 @@ Description
     generate the entry itself. So
     - codeStream reads three entries: 'code', 'codeInclude' (optional),
     'codeOptions' (optional)
-    and uses those to generate library sources inside constant/codeStream/
+    and uses those to generate library sources inside \f constant/codeStream/
     - these get compiled using 'wmake libso'
     - the resulting library is loaded in executed with as arguments
-            const dictionary& dict,
-            Ostream& os
+    \code
+        (const dictionary& dict, Ostream& os)
+     \endcode
     where the dictionary is the current dictionary.
     - the code has to write into Ostream which is then used to construct
     the actual dictionary entry.
@@ -41,6 +42,7 @@ Description
 
     E.g. to set the internal field of a field:
 
+    \verbatim
     internalField  #codeStream
     {
         code
@@ -56,19 +58,23 @@ Description
         #{
             #include "fvCFD.H"
         #};
+
+        //- Optional:
         codeOptions
         #{
             -I$(LIB_SRC)/finiteVolume/lnInclude
         #};
     };
+    \endverbatim
 
 
-    Note the #{ #} syntax which is just a way of inputting strings with embedded
-    newlines.
+    Note the \c \#{ ... \c \#} syntax is a 'verbatim' input mode that allows
+    inputting strings with embedded newlines.
 
     Limitations:
     - '~' symbol not allowed inside the code sections.
-    - probably some other limitations (uses string::expand which expands $, ~)
+    - probably some other limitations (uses string::expand which expands
+      \c \$ and \c ~ sequences)
 
 SourceFiles
     codeStream.C
@@ -106,6 +112,20 @@ class codeStream
 
 public:
 
+    // Static data members
+
+        //- Name of the code template to be used
+        const static word codeTemplateName;
+
+        //- Name of the code template environment variable
+        //  Used to located the codeTemplateName
+        const static word codeTemplateEnvName;
+
+        //- Name of the code template sub-directory
+        //  Used when locating the codeTemplateName via Foam::findEtcFile
+        const static fileName codeTemplateDirName;
+
+
     //- Runtime type information
     ClassName("codeStream");