new plugin to extract the geometry edges

fix fpe

fix popup+make depend

- recompute min/max in view after adaptation
- cleanup superfluous resets of TimeStepMin/Max

Rewrote the background mesh code to use the new post-pro octree instead
of the old brick stuff. It's 100x faster ;-)

better averaging

typo

make depend

new plugin ExtractElements to extract elements whose values are comprised
in some interval

rewrote the smooth normal routines:

- the averaging is now done by clusters, which is much better for
  geometries that have sharp edges  (it's a little slower, but the
  visual results are much better)
- there is now only a single smooth normal container in the mesh
  (instead of one per surface)

- new button under the graphic window to temporarily disable mouse
  selection (speeds-up redrawing of very large models + permits to
  rotate/zoom-in a model in selection mode even when the whole screen
  is full of selectable entities--e.g. a surface mesh)

- new "lasso" selection mode (to select entities using the same kind
  of lasso as the lasso zoom: just Ctrl+click, then drag the mouse in
  selection mode; the shortcuts are the same as for the lasso zoom)

- it is now possible to unselect entities using the middle mouse button
  (only for the creation of physicals at the moment; not sure if it's
  useful in the other cases)

- new button in visibility browser to invert the current selection
  (very useful e.g. when multiple physical entities are associated
  with a given elementary entity, in order to "peel" away the model
  when adding new physicals; cf. philou)

- changed meaning of Escape shortcut (cancel lasso or toggle mouse
  selection) + restore standard fltk Escape handling for all dialog
  windows

- updated copyright string

- new mesh label mode (coordinates); all label types are now also
  available for mesh vertices

- added option in 'Print Option' dialog to disable printing of help
  strings

- added a comment string with the date when creating a new file

- new snapping grid for adding points in the GUI

make depend

add line elements in octree + little nicer Probe drawing

upgrade triangle to version 1.6

add fixme for extract volume in 2D (orientation of quads)

moving all external code to contrib subdirectory

Please don't load solver plugins by default: for the vast majority of users,
the structural solver options don't make any sense.

Just add Solver.Plugins=1 in your option file if you need that stuff.

New plugin to compute the modulus and the phase of a complex-valued field
in-place, in one simple step. One could already do this with Plugin(Evaluate),
but it was a little bit cumbersome.

fixed crash when using Plugin(CutParametric) in a script ("v->" -> "v1->")

fixed crash when using Plugin(Evaluate) in a script ("v->" -> "v1->")

removed unused stuff + handle SURF_DISCRETE in MeshDiscreteSurface

polih previous commit