add the sup of a function on a mesh
real uinfty=sup(Th,abs(f));
real uhinfty=sup(uh); 


Newton algorithm.
Non Linear Conjugued Gradient.

automatique scheme for time depend problem:
dt(u) or u_t

implicite:
problem a(u,v, sheme=Euler , dt = 0.1, tinit = 0, tfinal = 10 , previous=[u1]) = 
  int2d( u_t*v + dx(u)*dx(v)+dy(u)*dy(v) ) ;
  
explicit:
problem a(u,v, sheme=thetaScheme(0.5) , dt = 0.1 , tinit = 0  , tfinal = 10 , previous=[u1]) = 
  int2d( u_t*v) + int(dx(u1)*dx(v)+dy(u1)*dy(v)) ;


  
Client/Server version (src/ide/FreeFem++-cs) TODO list:
-------------------------------------------------------

(Most important first)

o [lehyaric] Remove message "Enter ? for help" from the graphical
   window (see in MeshDraw.cpp, Show())

o [lehyaric] Allow bigger FreeFem++ programs (more than 10KBytes) to
   go through sockets

* Compile for Microsoft Windows (DONE)

o [lehyaric] Add more graphical tools (postscript output, ...)
   See standard FreeFem++ X11 version for list of tools

* [lehyaric] Optimize client/server communication through socket by
   using binary data instead of strings (DONE)

o [lehyaric] Save and reload window settings and configuration

o [lehyaric] List of recently opened files

o [lehyaric] Option to run server on remote machine

o [lehyaric] Properly define postscript output location

* [lehyaric] Coloring in output window (and associate commands like
   error display on mouse clicks) (DONE)

o [lehyaric] Macro highlighting in editor (see
   example++-tutorial/nolinear-elas.edp)

* [lehyaric] Syntactically correct parameter highlighting (instead of
   just recognizing words) in editor window (DONE)

* Use more efficient select() call instead of poll()
   in cs.cpp (NO LONGER NEEDED)
