7908b8d7be2a2992c57cd549054eda7ce46e4b44 ("m-lua-scripting: allow
converting GValue holding NULL objects to Lua") accidentally added a second
refcount. As a result, the objects are never freeded.
Remove the second refcount to fix this.
The load functions used to do 3 things:
- push the sandbox function on the stack
- load the file and push it as a function on the stack
- call the sandbox (or the file)
Now there are separate functions to do these 3:
- wplua_push_sandbox
- wplua_load_*
- wplua_pcall