improve mod_perl config functions to allow reaching all any depth of the config hash

Currently you can only access one level deep into the hash, this means there is no reasonable way to setup multiple servers outside of doing someting stupidl ike server_one, server_two_host, server_two_pass, etc.. 

This is easily fixable by making the existing mod_conf_foreach function recursive and a little smarter about how it does callbacks, alternatively we could do this with a state machine
