Fix for switch in Hilfe. Reported by Mr. Bear
Calendar.mkrules: Ignore tzdata files that aren't used.

Calendar.mkrules is only interested in the tzdata files that contain
timezone rules, so ignore known tzdata files that aren't such.

Also adds a corresponding .gitignore file.
Compile with SSL3_DEBUG
Allow SHA224, SHA256, SHA384 and SHA512 for RSA and ECDSA signatures.
Improved alert debug messages.
Revert "Allow SHA224, SHA256, SHA384 and SHA512 for RSA and ECDSA signatures."

This reverts commit 78838d2ba6a1f75a985a073479a66b6c473d54f2.

This commit violated RFC 5246 7.4.1.4.1:

  If the client does not send the signature_algorithms extension, the
  server MUST do the following:

  -  If the negotiated key exchange algorithm is one of (RSA, DHE_RSA,
     DH_RSA, RSA_PSK, ECDH_RSA, ECDHE_RSA), behave as if client had
     sent the value {sha1,rsa}.

  -  If the negotiated key exchange algorithm is one of (DHE_DSS,
     DH_DSS), behave as if the client had sent the value {sha1,dsa}.

  -  If the negotiated key exchange algorithm is one of (ECDH_ECDSA,
     ECDHE_ECDSA), behave as if the client had sent value {sha1,ecdsa}.
For compat: SHA1 yes, MD5 no. We should probably make a signature_algorithms in Context and use that instead of this for clients.