Lua state reuse does not work

[Rainer Jung]

I did a few lua tests and currently the reuse of lua states does not 
work. Unfortunately I don't yet see the root cause.

We are constantly creating new lua states, saving them to the pool and 
on the next request retrieve null and create a new state. When the 
server is shutdown, all of the states are cleaned up together. This is 
true for conn and thread scope and for prefork, worker and event. I'm 
using apr trunk.

Regards,

Rainer