Fix use of StateDir directive after r1852982:

* server/core.c (reset_config): Rename from reset_config_defines;
  tie core_state_dir to pconf lifetime in this cleanup.
  (core_pre_config): Adjust accordingly.

* modules/md/mod_md_config.c (md_config_post_config): Pick up base_dir
  from statedir in post-config phase so StateDir can influence it.

* modules/dav/fs/mod_dav_fs.c (dav_fs_create_server_config): Don't
  init lockdb_path here.  (dav_fs_post_config): New function; set
  lockdb_path based on configured statedir. 


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1857731 13f79535-47bb-0310-9956-ffa450edef68