* Configure: Try "imap.*"/"smtp.*"/"mail.*" first
Fix half of #3158.
Try "imap.ex.org"/"smtp.ex.org" and "mail.ex.org" first because if a server exists
under this address, it's likely the correct one.
Try "ex.org" last because if it's wrong and the server is configured to
not answer at all, configuration may be stuck for several minutes.
* Changelog
* Add test
LoginParamNew structure, which contained possible IMAP and SMTP
configurations to try is replaced with uniform vectors of ServerParams
structures. These vectors are initialized from provider database, online
Mozilla or Outlook XML configuration or user entered parameters.
During configuration, vectors of ServerParams are expanded to replace
unknown values with all possible variants, which are tried one by one
until configuration succeeds or all variants for a particular protocol
(IMAP or SMTP) are exhausted.
ServerParams structure is moved into configure submodule, and all
dependencies on it outside of this submodule are removed.
