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/parallelProcessing/reconstructPar/reconstructLagrangian.H

@@ -36,6 +36,7 @@ SourceFiles
 #ifndef reconstructLagrangian_H
 #define reconstructLagrangian_H
 
+#include "cloud.H"
 #include "polyMesh.H"
 #include "IOobjectList.H"
 #include "fvMesh.H"

applications/utilities/parallelProcessing/reconstructPar/reconstructLagrangianFields.C

@@ -47,7 +47,7 @@ Foam::tmp<Foam::IOField<Type> > Foam::reconstructLagrangianField
             (
                 fieldName,
                 mesh.time().timeName(),
-                "lagrangian"/cloudName,
+                cloud::subInstance/cloudName,
                 mesh,
                 IOobject::NO_READ,
                 IOobject::NO_WRITE
@@ -61,10 +61,10 @@ Foam::tmp<Foam::IOField<Type> > Foam::reconstructLagrangianField
     {
         // Check object on local mesh
         IOobject localIOobject
-        ( 
+        (
             fieldName,
             meshes[i].time().timeName(),
-            "lagrangian"/cloudName,
+            cloud::subInstance/cloudName,
             meshes[i],
             IOobject::MUST_READ,
             IOobject::NO_WRITE

applications/utilities/parallelProcessing/reconstructPar/reconstructPar.C

@@ -277,7 +277,7 @@ int main(int argc, char *argv[])
             (
                 readDir
                 (
-                    databases[procI].timePath()/regionPrefix/"lagrangian",
+                    databases[procI].timePath()/regionPrefix/cloud::subInstance,
                     fileName::DIRECTORY
                 )
             );
@@ -295,7 +295,7 @@ int main(int argc, char *argv[])
                     (
                         procMeshes.meshes()[procI],
                         databases[procI].timeName(),
-                        "lagrangian"/cloudDirs[i]
+                        cloud::subInstance/cloudDirs[i]
                     );
 
                     IOobject* positionsPtr = sprayObjs.lookup("positions");