Generate FL/fl_config.h rather than FL/abi-version.h

... as discussed in fltk.coredev in thread "RFC: introduce public
config header <FL/fl_config.h>", see:
https://groups.google.com/g/fltkcoredev/c/xLCs1AIXMVo/m/MHZpQggzAQAJ

- Rename abi-version.h to fl_config.h, rename input files,
  update dependencies, .gitignore, CMake, configure and Makefiles.

- Include Cairo options in FL/fl_config.h

- Rename FLTK_USE_CAIRO to FLTK_HAVE_CAIROEXT for consistency.

- Include <FL/fl_config.h> in config.h and wherever necessary,
  fix include order (move FL/Fl.H to the top) and more.

- Move USE_X11 to fl_config.h and rename to FLTK_USE_X11

- Do not include <config.h> in Cairo demo program which is no
  longer required in Cairo programs since FLTK 1.4.0

1 files changed, 1 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index c023a9bab..ade947dde 100644
--- a/Makefile
+++ b/Makefile
@@ -68,7 +68,7 @@ distclean: clean
 	$(RM) fltk-config fltk.list makeinclude
 	$(RM) fltk.spec
 	$(RM) FL/Makefile
-	$(RM) FL/abi-version.h
+	$(RM) FL/fl_config.h
 	$(RM) documentation/*.$(CAT1EXT)
 	$(RM) documentation/*.$(CAT3EXT)
 	$(RM) documentation/*.$(CAT6EXT)