luarocks_dir compatibility with luarocks 3.x (#1003)
luarocks_dir compatibility with luarocks 3.x (#1003)

luarocks 3.x supports one luarocks install with multiple lua versions.
archlinux already uses 3.x, debian and friends still use 2.x

this will change the directory structure in the release (not sure if that is important)

as documented in:
https://github.com/luarocks/luarocks/blob/master/CHANGELOG.md

> Breaking change: The support for deprecated unversioned paths (e.g. /usr/local/lib/luarocks/rocks/ and /etc/luarocks/config.lua) was removed, LuaRocks will now only create and use paths versioned to the specific Lua version in use (e.g. /usr/local/lib/luarocks/rocks-5.3/ and /etc/luarocks/config-5.3.lua).
koreader/koreader-base,NiLuJe/koreader-base,Frenzie/koreader-base,NiLuJe/koreader-base,Frenzie/koreader-base,NiLuJe/koreader-base,Frenzie/koreader-base,Frenzie/koreader-base,koreader/koreader-base,NiLuJe/koreader-base,koreader/koreader-base,koreader/koreader-base