wip/fltk2 2.1git NetBSD

FLTK (pronounced "fulltick") is a LGPL'd C++ graphical user interface toolkit for X (UNIX), OpenGL, and Win32. FLTK was designed to be small and modular enough to be statically linked, but also works fine as a shared library. FLTK also includes FLUID, an interactive user interface builder program.

FLTK 2.0 is an experimental branch and has been declared inactive, superseded by 3.0. Later FLTK 3.0 has been declared inactive too.

New applications should use the FLTK 1.4 API.