- simpler plugin script save

finished up first pass at remote view management:

* interactive stuff is now almost feature-complete (including
  multi-step, axes and adaptive refinement)

* plugins can now be executed on remote views

* renamed GmshRemote->ConnectionManager & GmshDaemon->GmshRemote

stuff, like plugin drawing

Encapsulate toolkit-dependent global drawing functions in new
drawContextGlobal class, and add a static drawContextGlobal to
drawContext, with a default version that does nothing.

This allows to have a completely virtualized drawing system: we can
now ship a library with a fully working graphic system, indepedent of
the widget toolkit. A client code just needs to subclass
drawContextGlobal to get working graphics (see
e.g. api_demos/mainAntTweakBar.cpp)

re-committing work from last two days after server crash:

- refactored old Geo code (new/delete)
- moved DrawPlugin to Plugin
- move from matheval to mathex
- move from Flu_Tree_Browser to Fl_Tree
- fixed crash in Triangulate plugin

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

  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

upgraded all plugins to work with the new post-pro.

This is done "cheaply" for now, by only using old-style list-based datasets.
Taking advantage of the abstraction (so that we can use the plugins on all
datasets) will require more work. The hooks for transparent data translation
are in place, but the actual translation has not been implemented yet.

moving to new post-processing database

                    *** WARNING ***

do not upgrade if you need plugins or adaptive views: these have not
been ported (yet) to the new database

                    *** WARNING ***

re-add SphericalRaise: it's easier than Warp (it's reversible!) to plot
radiation patterns

- new alt+r shortcut to switch range modes

- reimplemented subdivision of extruded meshes
- fix indent + unused var + gcc warnings all over the place

- rewrote selection code to use dynamic arrays, so that we should never
overflow the selection buffer again (even on huuuuge models)
- cleanup some leftovers "useing namespace std"

a new, more flexible plugin: Plugin(Warp)

new plugin to extract the geometry edges

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

- 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

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.

new plugins: Gradient, Curl and Divergence