Please bundle SDL2_ttf for wider audience

[VitoVan]

Many developers didn't use Cairo or Pango to draw text, instead they use SDL2_ttf.

[VitoVan]

Bundling SDL2_ttf should not be a problem, but bundling cl-sdl2-ttf and loaded through Quicklisp would require:

• libffi
• libffi-devel
• gcc

This seems a little overkill for a Windows user, and maybe even for a non-wizard Ubuntu user.

[VitoVan]

Maybe it's inevitable to bundle MSYS2 for Windows.

But what about Linux, the libffi-devel thing is kind of tricky, I really don't want to ask the user to install anything.

[VitoVan]

Maybe it's inevitable to bundle MSYS2 for Windows.

But what about Linux, the libffi-devel thing is kind of tricky, I really don't want to ask the user to install anything.

Maybe setting a CPATH would do for the ffi.h on Linux?

[VitoVan]

Or maybe we should leave this to the user, if you want it, just (ql:quickload :sdl2-ttf).

[VitoVan]

Let's make this a experimental branch

https://github.com/VitoVan/calm/tree/leca