Calculate p from pd (note p is still read in by the termo package) and correct thermo.

 * maybe okay to remove reflectParcel.C2 ?

  * prefix internal functions with _foam to prevent collisions
  * cleanup functions after use
  * centralized FOAM_VERBOSE info to etc/{bashrc,cshrc}

 * check for existing processor*/ before creating mesh
 * require processor dirs with -fields option
 * new -force option to remove existing processor*/
 * added usage for Doxygen

remaining bug:
 * -cellDist does not write cellDecomposition labelList when
   region0/ does not already exist