In-a-dyn v2.1

Changes

• Use HTTPS instead of HTTP by default
• Support for disabling HTTPS for checkip-server, per provider.
  Idea from Valery Frolov
• Add -I,--ident=NAME option for syslog+pidfile name
• Deprecate --pidfile=NAME option in favor of --ident=NAME

Fixes

• Issue #150: Custom update URL parser fixes
• Issue #151: Support for detecting OpenSSL v1.1
• Issue #144: Clarify use of public vs private IP. It is possible
  to register private IP addresses in a public DNS
• Clarify --foreground option in man page
• Document minimum required versions of libite and libConfuse
• Portability fixes, replace __progname with a small function,
  replace %m with %s and strerror(errno).