Piped error loggers should use the reliable pipes,

i.e. they should be automatically restarted when they die
similar to what happens for access loggers.

Patch makes error loggers use the same code path as
access loggers.

Side effect: patch adds ap_server_root_relative() to the error
logger path before spawning.

Reviewed by R. Pluem.

Patch needs to be tested on Windows.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@735516 13f79535-47bb-0310-9956-ffa450edef68