Issue with latest LuaRocks

[rpavlik]

Newer versions of luarocks changes how it interprets the keys for installing, so instead of getting a lxsh directory with an init.lua file in it, I get the lxsh directory with an init subdirectory containing init.lua. You could change the rockspec to work with these newer versions, but that would break the older ones. IMHO, the best solution (aside from an upstream special-case in luarocks) is to rename init.lua to lxsh.lua and make the corresponding changes to the rockspec and makefile.