use while (runTime.loop() { .. } where possible in solvers

- change system/controlDict to use functions {..} instead of functions (..);
  * This is internally more efficient
- fixed formatting of system/controlDict functions entry

- pedantic change: use 'return 0' instead of 'return(0)' in the applications,
  since return is a C/C++ keyword, not a function.

applications/test/LduMatrix/LduMatrixTest3.C

@@ -53,9 +53,8 @@ int main(int argc, char *argv[])
 
     Info<< "\nStarting time loop\n" << endl;
 
-    while (runTime.run())
+    while (runTime.loop())
     {
-        runTime++;
         Info<< "Time = " << runTime.timeName() << nl << endl;
 
 #       include "readPISOControls.H"
@@ -143,7 +142,7 @@ int main(int argc, char *argv[])
 
     Info<< "End\n" << endl;
 
-    return(0);
+    return 0;
 }