Merge pull request #5 from techdivision/0.5.8-beta

digest authentication
Set keep-alive max requests to 100 + timeout to 75 seconds => nginx default values
Re-Intergrate automatic worker restart when shutdown after a number of requests
Merge pull request #47 from wagnert/0.5.8-beta

Re-Intergrate automatic worker restart when shutdown after a number of requests