OSspecific: altered file tests

- removed the previously added fileName type(), isDir(), isFile() methods.

- added optional bool parameter to isFile() function to explicitly
  enable/disable the check for gzip files.

- fixed minor bugginess where the default usage of isFile() would result in
  false positive matches.

- be slightly more stringent and use isDir() and isFile() instead of
  exists() function when we actually know the expected type.

applications/utilities/mesh/conversion/Optional/ccm26ToFoam/ccm26ToFoam.C

@@ -615,7 +615,7 @@ int main(int argc, char *argv[])
     {
         fileName ccmFile(args.additionalArgs()[0]);
 
-        if (!exists(ccmFile))
+        if (!isFile(ccmFile))
         {
             FatalErrorIn(args.executable())
                 << "Cannot read file " << ccmFile

applications/utilities/mesh/conversion/tetgenToFoam/tetgenToFoam.C

@@ -129,14 +129,14 @@ int main(int argc, char *argv[])
         Info<< "Reading .face file for boundary information" << nl << endl;
     }
 
-    if (!exists(nodeFile) || !exists(eleFile))
+    if (!isFile(nodeFile) || !isFile(eleFile))
     {
         FatalErrorIn(args.executable())
             << "Cannot read " << nodeFile << " or " << eleFile
             << exit(FatalError);
     }
 
-    if (readFaceFile && !exists(faceFile))
+    if (readFaceFile && !isFile(faceFile))
     {
         FatalErrorIn(args.executable())
             << "Cannot read " << faceFile << endl

applications/utilities/mesh/generation/blockMesh/blockMeshApp.C

@@ -108,7 +108,11 @@ int main(int argc, char *argv[])
         (
             new IOobject
             (
-                ( dictPath.isDir() ? dictPath/dictName : dictPath ),
+                (
+                    isDir(dictPath)
+                  ? dictPath/dictName 
+                  : dictPath
+                ),
                 runTime,
                 IOobject::MUST_READ,
                 IOobject::NO_WRITE,

applications/utilities/mesh/manipulation/setSet/setSet.C

@@ -746,7 +746,8 @@ int main(int argc, char *argv[])
 
         Pout<< "Reading commands from file " << batchFile << endl;
 
-        if (!exists(batchFile))
+        // we also cannot handle .gz files
+        if (!isFile(batchFile, false))
         {
             FatalErrorIn(args.executable())
                 << "Cannot open file " << batchFile << exit(FatalError);

applications/utilities/mesh/manipulation/splitMeshRegions/splitMeshRegions.C

@@ -627,7 +627,7 @@ autoPtr<mapPolyMesh> createRegionMesh
         Info<< "Testing:" << io.objectPath() << endl;
 
         if (!io.headerOk())
-        //if (!exists(io.objectPath()))
+        // if (!exists(io.objectPath()))
         {
             Info<< "Writing dummy " << regionName/io.name() << endl;
             dictionary dummyDict;