[Bf-docboard] Modelling chapter refactoring

[Bastien Montagne]

Hi every body

I’ve put a first (work in progress) version of my proposition for 
refactoring the “modelling” chapter – it turned out that would involve 
also some (small) modifications in the “manipulation” sub-part of the 
“interaction in 3D” chapter.

Of course, all this is in the sandbox 
(http://wiki.blender.org/index.php/Meta:Sandbox/Modelling_Refactor/Manual), 
with detailed explanations.

I will continue the work, and hope to propose a “definitive complete” 
version in about two weeks – but I’m nevertheless waiting for your 
comments and suggestions ;)

Regards,
Bastien.

PS: If anyone know the purpose of the “sharp” flag of edges (i.e. which 
tool use it), I’d like to learn it ;)