Make it easier to build with Lua. Remove compiler warnings.
diff --git a/src/Makefile b/src/Makefile
index b01029f..62c5835 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -405,9 +405,8 @@
# LUA
# Uncomment this when you want to include the Lua interface.
#CONF_OPT_LUA = --enable-luainterp
-# Lua installation dir (also in LUA_PREFIX environment variable)
+# Lua installation dir (when not set uses $LUA_PREFIX or defaults to /usr)
#CONF_OPT_LUA_PREFIX = --with-lua-prefix=/usr/local
-#CONF_OPT_LUA_PREFIX = --with-lua-prefix=/usr
# MZSCHEME
# Uncomment this when you want to include the MzScheme interface.