Include directives no longer refuse to process symlinks on

directories. Instead there's now a maximum nesting level
of included directories (128 as distributed). This is configurable
at compile time using the -DAP_MAX_INCLUDE_DIR_DEPTH switch.

PR: 28492


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@103472 13f79535-47bb-0310-9956-ffa450edef68