Switched from old hashing functions to use Bob Jenkins' hash routine

- If the underlying type is contiguous, FixedList hashes its storage directly.
- Drop labelPairHash (non-commutative) from fvMeshDistribute since
  FixedList::Hash does the right thing anyhow.
- Hash<edge> specialization is commutative, without multiplication.
- Hash<triFace> specialization kept multiplication (but now uLabel).
  There's not much point optimizing it, since it's not used much anyhow.

Misc. changes

- added StaticAssert to NamedEnum.H
- label.H / uLabel.H : define FOAM_LABEL_MAX, FOAM_ULABEL_MAX with the
  values finally used for the storage.  These can be useful for pre-processor
  checks elsewhere (although I stopped needing them in the meantime).

src/OpenFOAM/primitives/strings/string/string.H

@@ -47,6 +47,7 @@ SourceFiles
 #define string_H
 
 #include "char.H"
+#include "Hasher.H"
 
 #include <string>
 #include <cstring>
@@ -92,7 +93,7 @@ public:
         hash()
         {}
 
-        inline unsigned operator()(const string&) const;
+        inline unsigned operator()(const string&, unsigned seed = 0) const;
     };
 
 

src/OpenFOAM/primitives/strings/string/stringI.H

@@ -198,19 +198,11 @@ inline Foam::string Foam::string::operator()(const size_type n) const
 
 inline unsigned Foam::string::hash::operator()
 (
-    const string& key
+    const string& key,
+    unsigned seed
 ) const
 {
-    const size_type len = key.length();
-    const char *data = key.data();
-
-    register unsigned val = 0;
-    for (register size_type i=0; i < len; ++data, ++i)
-    {
-        val = (val << 1) ^ *data;
-    }
-
-    return val;
+    return Hasher(key.data(), key.size(), seed);
 }
 
 // ************************************************************************* //