Let product keys to be send after partly satisfying the order

Hello,

I have played with your nice module and I came with patch that makes this superb module even better! The main reason for doing this was that my customer wanted to be able to send missing product keys to already completed orders. I made some minor modifications to the uc_product_keys.module file.

The logic is now:

• Complete order
• Look for product keys and send them
• If there are some missing product keys, set the order state to pending.
• (assume that maintainer added the keys) after setting the order state to "complete", fetch the number of already sent keys, validate it against the order object. Are there some keys that should be sent? Yes? Let's send them :-)

Maybe it is not as good solution to be included in the main branch, but just in case someone was in same need as I was.

The patch is attached.

Regards

Lukas