Allow multiple balancermembers with the same url

Currently you can't set multiple balancermembers with the same url even
if they are bind to different balancers.

This commit fixes that unwanted behaviour.
Merge pull request #830 from roidelapluie/Allow-multiple-balancermember-with-the-same-url

Allow multiple balancermember with the same url
function to munge booleans to httpd's On/Off

this function tries to recognize booleans of any kind and convert
(normalize) them httpd's accepted On/Off.
Failing that, it will simply return the string it was passed. As such it
can be used, for instance for:

    $server_signature = true
    $server_signature = false
    $server_signature = 'mail'
Merge pull request #782 from igalic/bool2httpd-function

function to munge booleans to httpd's On/Off