ENH: improve controls for Time (issue #910)

- relocate some standard functionality to TimePaths to allow a lighter
  means of managing time directories without using the entire Time
  mechanism.

- optional enableLibs for Time construction (default is on)
  and a corresponding argList::noLibs() and "-no-libs" option

STYLE:

- mark Time::outputTime() as deprecated MAY-2016

- use pre-increment for runTime, although there is no difference in
  behaviour or performance.

applications/utilities/mesh/advanced/PDRMesh/PDRMesh.C

@@ -1021,7 +1021,7 @@ int main(int argc, char *argv[])
 
     if (!overwrite)
     {
-        runTime++;
+        ++runTime;
     }
 
     Info<< "Writing mesh without blockedCells to time " << runTime.value()
@@ -1157,7 +1157,7 @@ int main(int argc, char *argv[])
 
     if (!overwrite)
     {
-        runTime++;
+        ++runTime;
     }
 
     // Change the mesh. Change points directly (no inflation).