Use API instead directly obtaining worker and balancer.

Add BalancerStickySession and BalanceMember directives.
Add workers and balancers to create and merge config.

Submitted by: mturk


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@104567 13f79535-47bb-0310-9956-ffa450edef68