make makefly Lua 5.2+ compatible

[tst2005]

There are some work to do to be able to run makefly with Lua >= 5.2

• require()
• setfenv()

[blankoworld]

I planned to have a look for v0.5 version. Cf. http://forge.depotoi.re/issues/339

I also see that setfenv make problems in bin/markdown.lua and that some regular expression need to be modified.

I saw that its seems to be an habit that new version of Lua are not compatible between them. And this make people to leave the project and the language. :'(

[blankoworld]

I found this markdown script, set to work for Lua 5.2 : https://github.com/speedata/luamarkdown