Enhancements

#1076 - It's now possible to change the contact email registered with Let's Encrypt and also to provide multiple contact addresses.
#1070 - The ACME-DNS validation plugin now verifies if the CNAME records has been correctly set up, preventing common configuration problems from showing up during (pre)validation. This also enables limited support for unattended operation with this plugin. Certificates for domains that have previously been setup with ACME-DNS can now be re-created or modified from the command line.

Bug fixes

#1067 - Improved checking of DNS validation, i.e. following CNAME- and NS-records recursively to get to the final authoritative, canonical value. With much help from @ericcan and @davidpeden3
#1068 - FTP installation not offered for IIS 7.5, reported by @Sysdmin
#1071 - Fix the CentralSsl store plugin not working properly with when PrivateKeyExportable was set to False, which is the default, first reported by @Joaquim3
#1080 - Fix an error when piping the output from wacs.exe to a file or other program, reported by @hanschou