physical tags, partitioning, second order prisms

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M    Common/LuaBindings.cpp
M    Geo/MVertex.cpp
M    Geo/GVertex.h
M    Geo/MVertex.h
M    Solver/dgAlgorithm.cpp
M    Solver/TESTCASES/ForwardFacingStep.lua
M    Solver/dgSlopeLimiter.cpp
M    Solver/dgSystemOfEquations.cpp
M    Solver/dgConservationLawPerfectGas.cpp

never ever change the immutable vertex numbers: otherwise we cannot use
our algorithms from outside with prescribed boundary meshes

-> use MVertex::_index instead

(renamed setNum to forceNum to make sure we don't use setNum by mistake)

make MElement and MVertex thread-safe by guarding _globalNum

- moved GUI to FlGui + added experimental QGui to test Qt

- fixed most MSVC and gcc compiler warnings

- converted some remaining tabs to whitespace (that's why the patch is
  so large; please try to remember to indent with 2 spaces and not
  tabs when you commit stuff to CVS)

- merged modified patch from Konstantinos Poulios to allow saving
  physical/partition as element tags in mesh formats that don't
  support them natively

added createTopology when Merging a MSH File and implemented discreteEdge

setNum() should change _globalNum

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

consolidate parametricCoordinates with reparamMeshVertexOnFace

cleanup high order

   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, ...)