Timeouts for email domain DNS check

It is no fun to wait more than 10 seconds for AgentTicketEmail or so
in the web interface
Cache Mail::Address->parse

calling it repeatedly, for example from ArticleGet can be quite
costly, and ArticleGet calls it two to three times (indirectly)
for each email address, and potentially many times more if the same
email address appears multiple times.

Since Kernel::System::EmailParser objects are short-lived and
Mail::Address objects rather small, the additional memory use
is not a problem.

With warm caches, this reduces the time spent in ArticleGet from
420ms to 230ms on a fairly large ticket.
Fixed bug#10055 - Queue-Treeview not working correctly.
Fixed bug#10049 - Transition names in path edit screen ordered by ID instead of name.
Fixed bug#10044 - PendingDiffTime removes 2013 (current year) when reaching end of the year.
Fixed bug#7820 - inexact german translation in ticket conversation.
Added new unit test for URL conversion (part of fix for bug#7822).
Fixed bug#10062 - Text label indent for locale RU - AgentTicketViewCompose.
Fixed: Service selection unavailable if customer selection is possible (bug#10059).
Fixed bug#10066 - Required field isn't marked in AgentTicketCustomer.
Fixed bug#10064 - Translated fields loose sorting in Activity Dialog admin screen.
Fixed bug#9109 - Printing ticket does not show the full subject line.
Fixed bug#4512 - HTMLUtils ToAscii forces line breake on fixed line-length 78.
Fixed bug#4663 - browsing article tree by 'next / down' and 'previous / up' buttons.
Fixed bug#7792 - Ticket-Action "Change Queue" is hardcoded and should be called "Queue" only.
Fixed: Owner and Responsible are mandatory if enabled (bug#10058).
Fixed: Wrong error message if Transition contains no transition actions (bug#10070).
Revert "Fixed bug#4512 - HTMLUtils ToAscii forces line breake on fixed line-length 78."

This reverts commit b5a4ade38efb356f5c91f1c14ffd11a9444b0dfd.

Conflicts:
	CHANGES.md
Removed duplicate line.
Merge branch 'master' of git.otrs.com:otrs/otrs