STYLE: manage dictionary inputMode directly within entry class

- The logic for switching input-mode was previously completely
  encapsulated within the #inputMode directive, but without any
  programming equivalent. Furthermore, the encapsulation in inputMode
  made the logic less clear in other places.

  Exposing the inputMode as an enum with direct access from entry
  simplifies things a fair bit.

- eliminate one level of else/if nesting in entryIO.C for clearer logic

- for dictionary function entries, simply use
  addNamedToMemberFunctionSelectionTable() and avoid defining a type()
  as a static. For most function entries the information is only used
  to get a name for the selection table lookup anyhow.

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

@@ -58,7 +58,7 @@ namespace Foam
 class dictionary;
 
 /*---------------------------------------------------------------------------*\
-                           Class functionEntry Declaration
+                        Class functionEntry Declaration
 \*---------------------------------------------------------------------------*/
 
 class functionEntry
@@ -71,10 +71,10 @@ class functionEntry
         static token readLine(const word& key, Istream& is);
 
         //- Disallow default bitwise copy construct
-        functionEntry(const functionEntry&);
+        functionEntry(const functionEntry&) = delete;
 
         //- Disallow default bitwise assignment
-        void operator=(const functionEntry&);
+        void operator=(const functionEntry&) = delete;
 
 
 public:
@@ -82,7 +82,7 @@ public:
     // Constructors
 
         //- Construct from keyword, parent dictionary and Istream
-        functionEntry(const word&, const dictionary&, Istream&);
+        functionEntry(const word& key, const dictionary& dict, Istream& is);
 
 
     // Member Function Selectors
@@ -105,7 +105,7 @@ public:
         (
             const word& functionName,
             dictionary& parentDict,
-            Istream&
+            Istream& is
         );
 
         declareMemberFunctionSelectionTable
@@ -127,12 +127,12 @@ public:
         (
             const word& functionName,
             const dictionary& parentDict,
-            primitiveEntry&,
-            Istream&
+            primitiveEntry& entry,
+            Istream& is
         );
 
         //- Write
-        virtual void write(Ostream&) const;
+        virtual void write(Ostream& os) const;
 };