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

CGNS I/O rewrite - alpha version

- 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

******************************
*   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

untabify

introduce notion of entities in PViewData (in prepa for gmodel stuff)

- clean up GModel API (xxByTag -> getXx, numXx -> getNumXxes, ...)

	-) 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

fix BDF small field export on Windows (apparently Windows does not conform
to ANSI C and uses 3 digits in %e instead of 2)

cleanup previous commit + move "carve hole" routines in separate file

cleaned last gcc warnings

tagging gmsh_2_0_0

- subclassing higher order vertices is not a good idea--it makes the
identification hard in the I/O layer. So let's just store a char for
the order like we did in the old versions

- fixed license.texi and in License.cpp

- removed unused GEntity::inClosure()

- nicer display of second order elements (don't draw internal edges)
- nicer display of second order vertices (color like in 1.65)

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

- second order nodes on geometry by default
- better min/max range computation for cut planes
- more work on fourierModel

- setParameter in MVertex
- revert() for quad
- minor cleanups in I/O code
- start work on overlap mesh in fourierModel

- start work on fourierModel
- add support for pyramids in BDF (it's not in the official spec I have
  here, but all the files I found on the web use CPYRAM)

- finished Nastran BDF implementation (read+write in all BDF formats:
  free field, small field & long field)
- improved UNV and Medit import
- added detection of bad vertex indices in all import routines
- fixed bug in 2nd order quad constructor

Added support (both read and write) for the Nastran Bulk Data File
format (BDF).

This might need some adjustments depending on what the actual spec
is: I just reverse engineered some BDF files I found on the web :-)

add comments

reduce dependencies by putting the selection buffer stuff in its own file

small cleanups + start rewriting 2nd order stuff

Implemented new binary MSH file format (both read and write).

A 250Mb mesh file (6 million tetrahedra) is now read or written to disk in
less than 10 seconds (on my powerbook's slow hard drive).