Calculate first repsonse for admin started conversations

[dagfait]

Currently the first response time for conversation started by defacto is calculated based on the first conversation part. This is usualy the client, but this does not reflect the way that defacto response to the client. Some possible solutions:

1. Filter out all converstations started by defacto.
2. Remove the conversation from calculating the responce time, but still use it to calculating time spent solving.
3. Calculate the first response time based on the first repsonse of defacto after the first clients response.