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.
Merge branch 'dns-timeout' of https://github.com/moritz/otrs
Added a check to see if Dif'ed were installed per OPM.
Tidied.
Rename new method to _MailAddressParse

as suggested by @mgruner
Fixed bug#10077 - regular expressions in postmaster filter return 1 if no regex match.
Fixed: Installer fails when special characters in database user's password (bug#10056).
Fixed: Installer: error log after creating mysql database (bug#10078).
Fixed bug#9723 - TicketAccountedTime stat does not run on Oracle with many tickets.
Fixed: Wrong article type with external ticketnumber recognition i.c.w. follow-up reject option (bug#9702).

Conflicts:
	CHANGES.md
Added functionality to disable access to tickets of other customers with the same customer company in customer interface (#1365).
Fixed bug#9650 - Special character in customer id breaks Open Tickets in AgentTicketZoom.
Fixed lost QueryCondition UnitTest of rel-3_2.
Added additional information to install commands for different distributions (see perl bin/otrs.CheckModules.pl -h) for more information.

New install commands for the following distributions:
debian, ubuntu, centos, fedora, rhel, redhat, suse, win32 (with active state perl)

usage: otrs.CheckModules.pl [-list|all]

   otrs.CheckModules.pl
       Returns all required and optional packages of OTRS.

   otrs.CheckModules.pl -list
       Returns a install command with all required packages.

   otrs.CheckModules.pl -all
       Returns all required, optional and bundled packages of OTRS.
Fixed: Problems with special characters in Kernel/System/WebUserAgent.pm (bug#10090).
Simplify code in Web::Interface{Agent,Customer}

No functional changes
Added UnitTests for bug#10077 - regular expressions in postmaster filter return 1 if no regex match.
Modified fix for bug#9959 - & breaks ExpandCustomerName.
Extended fix for bug#9959 - & breaks ExpandCustomerName.