time overhaul:

- ap_time_t is a 64-bit scalar, microseconds since epoch
- ap_exploded_time_t corresponds to struct tm with a few extras

probably broken on anything except linux.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@84413 13f79535-47bb-0310-9956-ffa450edef68