build: switch to lua-5.2.1
build: switch to lua-5.2.1

frobware/cmd-key-happy,frobware/cmd-key-happy,frobware/cmd-key-happy,andymcd/cmd-key-happy,andymcd/cmd-key-happy,jaequery/cmd-key-happy,jaequery/cmd-key-happy,andymcd/cmd-key-happy,frobware/cmd-key-happy,andymcd/cmd-key-happy,andymcd/cmd-key-happy,jaequery/cmd-key-happy,frobware/cmd-key-happy