According top my testing 'SSL_SESSION_id2sz' is 4x faster with the use 'ap_bin2hex' instead of
apr_snprintf(..., "%02X" for each character.
Output is the same.

I have left the uppercase conversion, because I'm unsure if it is usefull or not.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1429559 13f79535-47bb-0310-9956-ffa450edef68