main core: Emit errors during the initial apr_app_initialize()

main core: Emit errors during the initial apr_app_initialize()
or apr_pool_create() (when apr-based error reporting is not ready).

This moves apr_app_initialize() into init_process (and indirects the
argv/argc parameters for this function) since the same error logging
is appropriate to either failure.

Note the change of the internal name create_process to init_process,
since create_process means something very different in apr-land.

(Replaces the misapplied commit r568762, already backed out).

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@568779 13f79535-47bb-0310-9956-ffa450edef68