[Fluxus] commits + oops

[Artem Baguinski]

hi

i've made a couple of tiny fixes:

1. stopped fluxus from complaining about missing characters when
switching to second editor (ctrl+2). the problem is GLUT related:
ctrl+2 has key code 0 at least on X11 version of glut, we then attempt
to build lisp code from that with sprintf("(something... #\%c ...)")
which is treated as "(something ... #\" and scheme complains about it.
My workaround is to do nothing if keycode is 0. I'm sure I haven't
broken any code - nobody could listen to that key code anyhow. Correct
approach would be to pass ctrl+digit as symbol constants - this way
we'd be platform independent as well (glut codes from ctrl+
combinations depend on platform, at least for digits)

2. in physics active/passive cylinder were building ODE's capped
cylinder geometry, but why? capped cylinder is a cylinder with half
spheres on either ends, when I (active-cylinder (build-cylinder 10
10)) I expect the shapes be identical. so I took liberty to change the
code to create normal flat-ended cylinder.

my cylindrical physics still doesn't look right, so I'll continue
investigating this.

oops:

when committing the latter I also committed my changes to SConstruct
which I needed to link against plt in custom place in presense of
globally installed different version of PLT), you can see the diff
here:

http://cvs.savannah.gnu.org/viewvc/fluxus/SConstruct?root=fluxus&r1=1.81&r2=1.82

to my eye it seems innocent, but sorry if I caused trouble. Let me know if so.

cheers,
artm