objectRegistry fixes

- objectRegistry gets a rename() that also adjusts the dbDir
- cloud reworked to use static variables subInstance and defaultName.
  This avoids writing "lagrangian" everywhere

string fixes
- avoid masking of std::string::replace in string.H
- avoid old strstream in PV3FoamReader

applications/utilities/postProcessing/dataConversion/foamToFieldview9/createSprayFields.H

@@ -21,7 +21,7 @@ List<IOField<vector>* > sprayVectorFieldPtrs
         (
             sprayScalarNames[fieldI],
             runTime.timeName(),
-            "lagrangian",
+            cloud::subInstance,
             mesh,
             IOobject::MUST_READ,
             IOobject::NO_WRITE
@@ -53,7 +53,7 @@ List<IOField<vector>* > sprayVectorFieldPtrs
         (
             sprayVectorNames[fieldI],
             runTime.timeName(),
-            "lagrangian",
+            cloud::subInstance,
             mesh,
             IOobject::MUST_READ,
             IOobject::NO_WRITE