Reworked lua.properties and a test file for the upcoming Lua 5.2.0 (still rc8, any day now...) attached. This is the last part of the highlighting updates for Lua 5.2.0.
Default is a common Lua 5.x set of words. Lua 4 is now not enabled but included. It is easy to configure the properties for a specific Lua versions: lua50, lua51, lua52, lua5x, lua4. Styles are unchanged, so the average Lua 5 user will probably not notice anything different except for Lua 5.2.0 support.