Merge r1750507, r1750553 from trunk:

Fix proxy balancer lbmethod --enable defaults to follow proxy_balancer

Small change to r952007, ensure we don't wipe out the $enable_foomod value
when that value is 'shared'. The 'yes', 'shared', 'static' and 'no' values
are all valid.


Submitted by: wrowe
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1750684 13f79535-47bb-0310-9956-ffa450edef68