srm,webdav,httpd: Log SSL handshake failures

Will log SSL failures, such as when clients try to use disabled features. Eg:

28 nov. 2014 10:21:53 (SRM-Gerds-MacBook-Pro-5) [] SSL handshake with localhost/127.0.0.1:62713 failed: SSLv2Hello is disabled

Target: trunk
Request: 2.11
Require-notes: yes
Require-book: no
Acked-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Acked-by: Paul Millar <paul.millar@desy.de>
Patch: https://rb.dcache.org/r/7539/