FLTK 1.4.x development snapshot

Intended to test glyph substitution via Pango with X11 backend.
This allows applications to render text using multiple fonts.

Also useful to test compatibility of packages with FLTK 1.4 API.
In general application using the FLTK 1.3 API should work out-of-the-box
with FLTK 1.4 too. Note: The ABI of the shared library is not compatible!