Use apr_temp_dir_get for htdigest and remove the dependancy on the external...

Use apr_temp_dir_get for htdigest and remove the dependancy on the external cp/copy command. Remove the OMIT_DELONCLOSE #ifdef because removing the temp file happens automatically through the apr_temp_dir_get() call.  Also some other misc cleanup of the code

Submitted by: Guenter Knauf <eflash gmx.net>
Reviewed by: bnicholes, jjclar, nd


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/APACHE_2_0_BRANCH@103207 13f79535-47bb-0310-9956-ffa450edef68