new "Background Mesh" command

- added little routine to save a post-pro view as a mesh file
- moved all post-pro I/O routines in a separate file

fixed ugly extrusion syntax (finally!)

extrusions are now specified in the same way as all other transformations
(the old syntax is still available, but is deprecated)

- 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

added small slider window to choose the z-clipping factor in real time.

FLTK is really awesome :-)

add links to new interactive tutorials

new shortcuts for alternative x, y, z views (still needs to be completed by dave)

- the fltk m#@!er f*!@ers changed the way FL_CTRL/FL_META shortcuts
are treated on the Mac. This patch forces FL_META (the "Apple key") for
all Ctrl shortcuts in the menu. I think this is the way most people on
Macs would expect the shortcuts to work anyway.

- fix metis readme+configure info

shorter intro

The current behavior of Gmsh when drawing 3D scalar fields is not coherent
with what is done in 2D: to draw filled iso-values or continuous maps in 3D,
we should ideally do volume rendering. Right now we draw the iso-values
(i.e., surfaces), which is both not coherent with the definition of
continuous maps or filled iso-values, but is also annoying when trying to
visualize fields that are constant per element (since in that case nothing is
displayed!)

Until we can do volume rendering, I've changed the behavior to draw the
solution on the boundary of the 3D elements. It's rather slow, but it's the
right thing to do visually.

apply patch from the Debian people

explain #list[]

- clarify Combine commands
- explain the funcdamental difference between post-pro options and post-pro plugins

generalized the solver interface to allow permanent listening on a
socket for whoever wants to connect (gmsh -listen)

the polling should also be less CPU hungry in this new version

next step is to add new commands to the protocol so that solvers can
directly transmit data to merge (geometry, mesh, etc.) in addition to
messages and filenames

- new option to choose the mesh element labels (element number, elementary
  entity number, physical entity number or partition number)

doc trsf surf orientation option

finer control of time/timestep display

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.

Removed the last bits of the "Discrete Surface/Line" stuff.

Gmsh can now simply read a .msh file, and use it as the boundary mesh
of a 3D mesh. For an example on how to do this, cf.
demos/sphere-discrete.geo.

This complements nicely the STL remeshing stuff: Gmsh can now
for example very easily be used to extrude surface meshes that
come from other tools.

reorder

removed remaining Discrete Line/Surface stuff

added small warning in automatically generated opt_* files

better help string for '-combine'

added all the missing "Combine" modes in the parser