use default line width to draw bounding boxes and axes

wording

draw string with min/max of the bounding box (very useful when we have no
geometry points to check the coorrdinates from!)

added comment about unknown origin of the code

Removed General.MovingLight option (confusing, and never really worked
anyway)

pretty print

add a bit more space between y-axis and labels

pretty print

pretty print

pretty print

set default position of 2d graphs 20 pixels more to the right

pretty print

- cleaned up the octree code (renamed some files, added copyright
  notices, indented everything)

- backported JF's doc from the texinfo file into the c++ code (the
  documentation is actually generated automatically by Gmsh with
  "gmsh -doc"!)

- replaced nPoints with nPointsU and nPointsV in CutGrid

- fixed a couple of printfs + removed some unused variables

- added new General.GraphicsFont option

- added GUI stuff for font selection, quadric subdivisions, selected
  lines

- improved Graph2D's handling of fonts

- removed Print.EpsFont and Print.EpsFontSize options

refined arrow editor

adding test-case where 2nd order algo generates hanging nodes

Merged options->general->light panel into options->general->aspect. This
is more consistent with what we do in options->geometry and options->mesh.

don't print the full progname on batch info line

doc -convert

"gmsh -convert file file" now also translates meshes into the newest
format (in addition to parsed->binary post-processing views)

small fix to be more predictable

cleaner cut plane tests

- added little GUI for mesh cutting plane
- added option to draw the intersecting layer as surfaces

modify alt+shift+l to match the old behaviour

document second order simplices

- order 2 doc is done
- order 2 drawing is fone

added drawing code for faces of haxahedra, prisms and pyramids

removed the Mesh.Solid option: it's not necessary anymore

added drawing code for faces of 2nd order tets