remove empty style tags
use more generic regex to allow possible attributes in empty style tag
add unittests
add another unittest
Improved HTMLUtils::ToAscii, thanks to Renée Bäcker.

Merge branch 'reneeb_htmlutils_avoid_backtracking_to_ascii' of github.com:reneeb/otrs

Conflicts:
	scripts/test/HTMLUtils/ToAscii.t
Fixed: PostMasterMailbox.pl hangs parsing mails (bug#10532).
Fixed: Service selection in GA Ticket Action allows multi select (bug#10578).
Squashed commit of the following:

commit 0b41aede7b331c3d9fd42c114a11cfbcfd0def36
Author: s7design <otrs@s7designcreative.com>
Date:   Thu Jun 19 14:00:15 2014 +0200

    multiselect change value to "0" in AdminGenericAgent

    http://bugs.otrs.org/show_bug.cgi?id=10578

Conflicts:
	CHANGES.md
	Kernel/Modules/AdminGenericAgent.pm

Conflicts:
	CHANGES.md
Fixed: "Previous Owner" don't use the FirstnameLastnameOrder configuration (bug#10559).

Conflicts:
	CHANGES.md
	Kernel/Modules/AgentTicketMove.pm
Merge remote-tracking branch 'upstream/master' into otrs-master