Lua 5.1 compatibility fix.
Changed my fix to match the common format.
Merge pull request #45 from SkyMarshal/master

Lua 5.1 compatibility fix.
Add missing headers
(issue #44)
Add function argument sections
Update document
Update code example
Add Lua install instruction
Update document
Add more assert
Change userdata spelling to match LuaState
Remove get prefix if the function does not push values
Merge pull request #1 from SteveKChiu/master

Update