orientation in extrusions

* removed unused stuff (more to come)
* moved remaining into Common

* implemented first rough draft of VTK mesh writer

  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

rewrote adaptive view stuff so we can use it on all types of views
(model-based, multi timestep, multi-mesh)

- deprecated "Complex Volume"

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

untabify

re-fix Field.h API dependency

fix shift/conflict reduce in parser introduced by Field stuff

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

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

bug fix: even when a For/EndFor loop was not entered, we still increased
ImbricatedLoop. This could lead to undefined behaviour with nested loops

Smoother Surface{list} = numsteps;

make sure we define  YY_NO_UNISTD_H on wind32

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)