Additional dependencies for OpenGL based renderers

[Shai Ayal]

Hi all,

Micheal and I are writing a graphics backend based on OpenGL and fltk.
This backend will introduce the following library dependencies for
octave:

gl
glu
fltk
ftgl
freetype2

to the best of my knowledge all of these libraries are present in
major linux distros, and all of them are compatible with windows (both
cygwin & MSVC) and Mac.

Please let us know if there is any problem with these dependencies.

Shai