This is intended for backwards compatibility with FLTK 1.3.x code
ported to 1.4.0.
Users defining FL_NO_DEPRECATE can compile old (1.3.x) code w/o
seeing lots of "deprecated" warnings. A legitimate use case is if
old (1.3) code is intended to be used with both FLTK 1.3 and 1.4.
FL_NO_DEPRECATE should NOT be defined if the user's code is targeted
at 1.4.x or later. Users should fix their code to be prepared for
the next minor release (e.g. 1.5.0).
Todo: document this.
Works now much better with old C99 and C++98 standard compilers.
Fixed: C++ comments in C files and headers included by C files.
There are still some warnings with C90 though but these would be
hard to fix and left as-is for now.
test/fractals.cxx: some arrays were too small by 1, or the compiler
warned at least (false positive?). Anyway, it's fixed now.
FL_OVERRIDE is defined as `override` for C++11 and higher
FL_OVERRIDE is defined as `override` for VisualC 2015 and newer
Don't interfere with Fl_Widget::override()
