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

fix bug in Evaluate (bad test for external view)

untabify

octree + CutGrid,CutParametric,Probe for model post views

added nodal interpolation functions & related stuff

remove BGMReset

re-fix Field.h API dependency

fix shift/conflict reduce in parser introduced by Field stuff

change new post API to allow multiple meshes in a single view (different
meshes in different steps)

- temp fix I/O to allow skipping $xx fields (this will be common
  with new post-pro)
- prune MElement (move mesh-only stuff in mesh algos)