FLTK 1.4.x development snapshot

Intended to test glyph substitution via Pango with X11 backend.
The "pango" option allows applications to render text using multiple fonts.

Disabling the "pango" and "xft2" options allows to build a lightweight FLTK
library that use X11 Core Fonts (rendered by the X server).

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!
