Allow update of "ReplyTo" in article

"ReplyTo" (if present) overrides "From" when it comes to route a response
from OTRS, so it should be updateable as well to stay in control.

Added test cases for ArticleUpdate.
Revert "Reverted changes in Kernel/System/UnitTest.pm."

This reverts commit 193e96f16989762fec112f3550de7f6a7104694d.
Revert "Improved handling of Data::Dumper to fix problems with hash sorting on perl 5.18."

This reverts commit 68c0b1ed2de8ef9075d6f25a9bbde2f2377f4e5d.
Revert "Improved IsDeeply() by using Data::Dumper."

This reverts commit 5d106529e75e096a11c2b7c3bda86417ff9ece13.
Improved handling of Data::Dumper to fix problems with hash sorting on perl 5.18.
Code cleanup.
Revert "Code cleanup."

This reverts commit 12906f0922c609cff3e5f397f5d19497e134f743.
Tidied.
Fixed: mails with an empty return-path header must not trigger auto responses in OTRS (bug#10309).
Fixed: Special character in customer id cuts off string. (bug#10300).

Conflicts:
	CHANGES.md

Conflicts:
	Kernel/Config/Files/Ticket.xml
Updated .gitignore for Fred.
Updated Japanese translation, thanks to Norihiro Tanaka.
Fixed: No use Ticket::Hook in AgentLinkObject (bug#9675).
Squashed commit of the following:

commit 7590ccbdf29c816238d1ee1764b36e1e92766930
Author: s7design <otrs@s7designcreative.com>
Date:   Tue Feb 25 14:45:52 2014 +0100

    [Bug 9675] No use Ticket::Hook in AgentLinkObject

    Added Ticket::Hook from config instead only Ticket#
Updated.
Enhanced test.
Fixed: When a ticket is deleted by generic agent job,  No such TicketID error (bug#9600).
Squashed commit of the following:

commit a2aa4c8422f94c917696674e8311e54898ce3514
Author: s7design <otrs@s7designcreative.com>
Date:   Wed Feb 26 01:50:14 2014 +0100

    Added next if !%Ticket for fixing message Need TicketID!  in Sys Log

commit 175c2d197d2578573921adc669b4adb4c319acb8
Author: s7design <otrs@s7designcreative.com>
Date:   Wed Feb 26 00:07:59 2014 +0100

    [Bug 9600] When a ticket is deleted by generic agent job, No such TicketID error

    Set Silent => 1 parameter in TicketGet function, that avoids the error message.

Conflicts:
	CHANGES.md
Fixed: Applying Filters to tickets in Status View or Queue View will log out session. (bug#10321).

Conflicts:
	Kernel/Output/HTML/Standard/AgentTicketOverviewSmall.dtl
Fixed: "Ouf of Office" shows inactive agents (bug#10299).
Squashed commit of the following:

commit fb1cfbc62337a37260f20baa1be95656e2c3ebb7
Author: s7design <otrs@s7designcreative.com>
Date:   Fri Feb 28 15:26:05 2014 +0100

    Changed: it work for invalid and invalid-temporarily.  Only valid user is showed in wiget

commit b3606b35ca774577799ecb83dfa16670561c8b77
Author: s7design <otrs@s7designcreative.com>
Date:   Tue Feb 25 21:49:28 2014 +0100

    Added USERID label in next, because I made mistake in previous commit

commit 876c4ce16cb8559ceb3155c6b1486c7cefdb7596
Author: s7design <otrs@s7designcreative.com>
Date:   Tue Feb 25 21:44:22 2014 +0100

    [Bug 10299] "Ouf of Office" shows inactive agents

    Added check if user is valid in wiget Out of office
Added fred Css for customer frontend.
Tidied.