Updated Slovenian translation
EBackend: Fix view leak when the client crashes

Remove the views from the closed/crashed backend when it is not being
used by any other connection.

https://bugzilla.gnome.org/show_bug.cgi?id=727431
Bug #720154 - [IMAPx] Silently recover from "Connection reset by peer" error

This is a partial commit for the bug, to address "Connection reset by peer"
errors, and even the BYE response from the server, more gracefully, like
reconnecting to the server and re-issue the job. There will be at least
one more commit for this bug report, for an NNTP provider.
Bug #720154 - [NNTP] Silently recover from "Connection reset by peer" error

The second, and final, part for this bug report, involving NNTP.
Bug #728167 - [IMAPx] Message headers downloaded twice
[IMAPx] Set local cache to never expire

This is not like an HTTP cache, the downloaded messages might not be
discarded periodically, because, apart of other things, it breaks
the "Copy for offline usage" option.
Bug #728414 - Deliver ESource data changes on idle

The data D-Bus property change is received in a gdbus dedicated thread,
thus any ESource property changes, caused by reload of the data file,
are also delivered in the same gdbus dedicated thread, which is wrong
when there are still left property bindings which update gtk widgets.
Update the ESource data on idle, to workaround this issue.