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

  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

untabify

api cleanup: use ByTag consistently (emphasises slowness of lookup)

* revert last commit from laurent
* new getNumElements() et getElement() functions in GEdge/Face/Region to
  simplify access to mesh

getTypeOfElements  and addThisTypeOfElement
to GEntities

added
getTypeOfElements  from Gentities and Physical Groups in GModel

A minimal Gmsh "null" model can now be embedded with no external dependencies

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

start reducing header pollution (removed Gmsh.h + cleaned up GModel & co)

	-) A bug has been corrected in the MeshAdapt Procedure
	-) The 2D Delaunay is now Anisotropic
	-) 3D Sliver removal procedure has been improved
	-) Curvilinear mesh generation has been slightly improved,
	   even if it is still far from done
JFR

changes for new projection surface interface

- prepare group of nodes in UNV (for Guillaume)
- prepare delaunay for connected volumes
- test 2nd patch from Michel for phase1() extrusion

bug: fixed nasty double free in GEdge destructor

don't try to interpolate a BoundaryLayerCurve!

cleanup msg

fix interactive modification of mesh attributes

prepare for extrusion