PV3FoamReader improvements

  - various GUI properties are now animateable="0"
    (meaning they no longer show up on the time-line)
  - move reader switches to the bottom of the GUI
  - move Lagrangian fields above pointFields for better visibility
  - basic support for multiple clouds
  - filter fields based on selection before looping over all the geometry bits
  - mesh conversion functions now return VTK mesh types for easier handling
  - faceZones mesh conversion had points/faces allocation reversed
  - updateInfo with every call to setTime() that changes the timeIndex
    This seems to be the only way to notice Lagrangian fields
  - restore displaying patchnames that got forgotten in the last commit
  - misc reorganization