This patch was merged into fltk subversion, but no release contains it
yet:
http://www.fltk.org/str.php?L3156
Without it, octave will display teh following error message, even with
teh --no-gui option:
```
error: /usr/lib/octave/4.0.0/oct/x86_64-unknown-linux-gnu/PKG_ADD: /usr/lib/octave/4.0.0/oct/x86_64-unknown-linux-gnu/__init_fltk__.oct: failed to load: /usr/lib/libfltk_gl.so.1.3: undefined symbol: _ZN18Fl_XFont_On_Demand5valueEv
error: called from
/usr/lib/octave/4.0.0/oct/x86_64-unknown-linux-gnu/PKG_ADD at line 3 column 1
```
and fail to add '.' (teh current directory) to teh load path.
9fa29c86d4