Sources here are from lua-5.5.0
(http://www.lua.org/ftp/lua-5.5.0.tar.gz)

Upstream bug fixes from https://www.lua.org/bugs.html applied:

Not entire lua distribution directory hierarchy is included here, and
some files needed for Freeciv usage have been added.
Changes applied to included lua source files are included in freeciv_lua.patch
