This contains third party libraries that are uncommon and are therefore shipped
with the Widelands source code for transparent compilation.

Changes
-------

Eris:
- Renamed main() to lmain() in luac.c and lua.c. The main() function defined there would hide our own main()
  where eris was linked in.

Tinygettext:
- Not using the base repository but the fork at `https://github.com/SuperTux/tinygettext`
  (commit 3a90f67ea59e5b792d634ed159526b040b2ce268 2024-02-16 20:24:54 UTC)
- Added ig and krl to list of languages in language.cpp
- CMakeLists: Removed version check

libmd:
- Based of commit d5b8e853989a73f8fff9dc4e00dccd0b691b84f9 (2024-02-21);
  heavily customised to embed it into our portable codebase and avoid name collisions with various system headers and libraries.
- Converted all files to C++, moved them into the "libmd" namespace, and renamed the include guards.
- Included some of the files that are normally generated semi-automatically.
- Removed file input functions specific to POSIX.
- Removed support for MD2, MD4, and RipeMD160.
