Add configuration for NetBSD, and refactor a bit the other configs.
Add configuration for NetBSD, and refactor a bit the other configs.

luarocks/luarocks,ignacio/luarocks,xpol/luarocks,luarocks/luarocks,rrthomas/luarocks,aryajur/luarocks,ignacio/luarocks,xpol/luarocks,rrthomas/luarocks,leafo/luarocks,tst2005/luarocks,starius/luarocks,xpol/luavm,tarantool/luarocks,starius/luarocks,tarantool/luarocks,keplerproject/luarocks,usstwxy/luarocks,xpol/luarocks,rrthomas/luarocks,keplerproject/luarocks,coderstudy/luarocks,luarocks/luarocks,lxbgit/luarocks,xpol/luavm,robooo/luarocks,lxbgit/luarocks,ignacio/luarocks,lxbgit/luarocks,coderstudy/luarocks,xiaq/luarocks,robooo/luarocks,aryajur/luarocks,tst2005/luarocks,coderstudy/luarocks,xpol/luarocks,xpol/luavm,xpol/luainstaller,usstwxy/luarocks,coderstudy/luarocks,xpol/luavm,starius/luarocks,xpol/luainstaller,tst2005/luarocks,usstwxy/luarocks,keplerproject/luarocks,xiaq/luarocks,aryajur/luarocks,usstwxy/luarocks,aryajur/luarocks,xpol/luavm,xiaq/luarocks,keplerproject/luarocks,lxbgit/luarocks,rrthomas/luarocks,xpol/luainstaller,tst2005/luarocks,leafo/luarocks,starius/luarocks,xpol/luainstaller,leafo/luarocks,robooo/luarocks,ignacio/luarocks,tarantool/luarocks,xiaq/luarocks,robooo/luarocks