- fix bb computation to avoid model jumping around when adding points in z=0 plane
- pass interpol matrices as ref

   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

untabify

make parser embeddable in code with other parser (yy->gmsh_yy)
more work on headers
fixed lots of gcc warnings

- fixed missing return value in OCCVertex::reparamOnFace

- added code to highlight orphan entities (dave's idea)

- added gui for incomplete second order elements

- removed ugly static variables in 1d algo

- made sure we remove all 2d order vertices before generating new ones

- reimplemented subdivision of extruded meshes
- fix indent + unused var + gcc warnings all over the place

Enhancement of the OCC interface

Plane surfaces are now recognized and the
usual gmsh "cross" is drawn correctly

occ work