Return 1 ('event handled') when our view receives an FL_SHOW event.   Does this matter?   It doesn't seem to hurt.

Use GL_LINE_STRIP rather than GL_LINE_LOOP when drawing an ellipsoid in PLANE style.  Make usetextaxes work for ellipsoids too.

Add tfm2euler() and tfm2xyzeuler(), translated from the perl.

Be consistent about which shell we're using in examples (bash now, not csh).

rgb888 => full-24-bit-color colorindex (like rgb565)
vec, vecscale, vecalpha commands
ctrl-S to toggle left/right stereo

New but undocumented features:
insist on using GLEW library  (need update to build instructions)
    snapshot's [-q jpeg_quality]
pixelaspect command

rgb888 => full-24-bit-color colorindex (like rgb565)
vector picking
vecalpha command
hot-key help ("?")
snapshot [-q jpeg_quality]
snapshot ... @  e.g. snapshot fred.@.%04d.png  => stereo-pair snapshot
pixelaspect command
don't crash in snapshot() if window has evaporated
insist on using GLEW library

If a color-index variable is named rgb888, it's interpreted as a full 24-bit color value:
  R*65536 + G*256 + B
with 0 <= R,G,B <= 255.

parti_snapshot(): if the pattern includes '@', emit a stereo pair of images, replacing @ with L and R.

   ?      print help message for hot keys
   ctrl-S toggle stereo left/right eyes
Safer sprintf for subcam report.

Use static GLEW library under MinGW (libglew32.a rather than libglew32.dll.a).

Use static GLEW library under mingw (libglew32.a rather than libglew32.dll.a).

Revamp FLTK configuration -- use fltk-config.  It tells us which libraries we need.  It also can tell us where to find libpng and libjpeg - either the versions built-in to fltk since 1.1.x, or else the system version if available.