redefinition of local curvature as the max in 2 directions

bug fix: orientation of face vertices of 4th order tetrahedra

corrected bug for higher order mappings in post views (supports q up to 4)

   1) this removes the asymmetry in all the routines involving mesh
      elements associated with points

   2) it makes it possible to use point-based datasets in the
      model-based post-processing module

  **********************************************************
    PLEASE TEST --- ESPECIALLY THE INPUT/OUTPUT ROUTINES!
  **********************************************************

* made GModel::getEntities() more efficient and generalized its use

Added static routine getInfoMSH - returns name and No. vertices for a
MSH type

INRIA input corrected and enhanced

- removed every "throw;", i.e., every throw that did not throw an actual exception.
  throw wihout args should ONLY be used in a catch{} to re-throw the same exception
  (for it to be handled in another catch clause)

- introduced GmshMessage callback class so that clients can easily implement
  their own message handling (see example in driverOCC.cpp)

* implemented first rough draft of VTK mesh writer

  did in high
* added mesh generation error log summary
* removed Parallel subdir (this is now handled by the message class)
* removed Box subdir and consolidated batch processing in a single
  routine
* made List_T into a class
* reduced dependencies in Pview*.h so we can eventually add the post-pro
  interface to the public API

- fix wrong vertex ordering in BDF

******************************
*   WARNING - PLEASE TEST    *
******************************

- changed I/O so that we NEVER change vertex number ids once a mesh has
been generated (or loaded)

- removed dataIndex from MVertex: stepData in PVewDataGModel now directly
uses the vertex/element number ids. This can lead to increased memory
use in corner cases (for which PViewDataList works fine, so it's not a
big deal), but it is simpler and faster

- moved some mesh creation utility routines in GModel::
- new MElementFactory
- fixed bad bg mesh index

untabify

added nodal interpolation functions & related stuff