Merge r1545286, r1545292, r1545325, r1545364, r1545408, r1545411 from trunk:

Use a normalized offset point for idlers... still need to worry
that atomics work as "expected", in this case that a add32 of a -1
is the "same" as dec32 (as far as effect on idlers)

r1545286 for eventopt


Use correct type...


Use offset which is smack dab in the middle.


naming suggestion re: trawick


Consistent types
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1569008 13f79535-47bb-0310-9956-ffa450edef68