Refactored mail backends.

We now use Net::SSLGlue::POP3 and Net::SSLGlue::SMTP which allow
us to use the same base modules for the SSLified backends as for
the 'plain' backends.

Therefore we drop the following modules:

 - Net::SMTP::SSL
 - Net::SMTP::TLS::ButMaintained
 - Mail::POP3Client
 - Net::POP3::SSLWrapper

Because we now use similar mail libraries for the connections, we can
use much less code; and we use 'use base' to derive the content of
the SMTP, IMAP, and POP3 backends in the SSLified versions.

Another benefit of using the Net::SSLGlue modules is that we can force
SSL certificate verification to 'off' - or we can pass verification
options to IO::Socket::SSL if we want to do this in the future.
Passing full options to IO::Socket::SSL was previously not possible
with all mail modules.
Updated the save widget for the process edit screen.
Added widgets to the PostMaster Filter module.
Merge branch 'master' of https://github.com/OTRS/otrs into master-nilei-AdminPostMasterFilterWidgets
Removed signature form Phone Inbound and Outbound templates.
Added missing entry.
Fixed bug#9666 Installing an invalid package cause an server error on package manager.
Extended fix for bug#9666 Installing an invalid package cause an server error on package manager.
Merge branch 'master-nilei-AdminPostMasterFilterWidgets' of https://github.com/nilei/otrs
Small fixes.
Merge branch 'master-nlei-ProcessManagement-ProcessEditSaveWidget' of https://github.com/nilei/otrs
Merge branch 'feature-mailrefactoring-mb-master' of https://github.com/mbeijen/otrs
Added changes entry.
remove URL from PDF output (ticket print)
Fixed missing escaping of IDs which caused problems in ITSMConfigurationManagement.
Fixed autocompletion. The new autocompletion wrapper did not work properly with the config option ActiveAutoComplete set to 0 in AgentTicketEmail and AgentTicketPhone.
Added possibility to negate postmaster filter settings, thanks to Renée Bäcker!

Squashed commit of the following:

commit e74dfe0fb9a53c749cec9e90a4716459bd355f92
Author: Martin Gruner <martin.gruner@otrs.com>
Date:   Thu Aug 15 14:30:39 2013 +0200

    Small fixes, added changes entry.

commit 697503daa8e22e0d5693d7eaeec812332c6f5519
Merge: b3ebf62 1c3a965
Author: Martin Gruner <martin.gruner@otrs.com>
Date:   Thu Aug 15 14:08:44 2013 +0200

    Merge branch 'reneeb_postmaster_not' of https://github.com/reneeb/otrs into postnegate

commit 1c3a9651738da773a5de2820ce277e09d9cb711c
Author: reneeb <github@renee-baecker.de>
Date:   Thu Aug 15 12:18:29 2013 +0200

    add column f_not to select statement

commit 3487d5d8f79540a8f8b4f062d1d65545da481377
Merge: 8fc2066 6f4b2d6
Author: reneeb <github@renee-baecker.de>
Date:   Thu Jul 25 01:09:57 2013 +0200

    resolve conflicts

commit 8fc20665ea1cce6d61096562708b3cde32592221
Author: reneeb <github@renee-baecker.de>
Date:   Thu Jul 25 01:04:32 2013 +0200

    add db changes to upgrade scripts

commit 90a321198e015761d2db3cc0baf0c83553b8d852
Author: reneeb <github@renee-baecker.de>
Date:   Thu Jul 25 00:42:27 2013 +0200

    add test mails

commit 4c866a53129c3605808a6720bb40ca08d403bb42
Author: reneeb <github@renee-baecker.de>
Date:   Mon May 20 06:19:53 2013 +0200

    add feature: negated regexes for postmaster filter

commit 6f4b2d6266ddd3ccdc41cd01d857f0b3bdc4a3b2
Author: reneeb <github@renee-baecker.de>
Date:   Mon May 20 06:19:53 2013 +0200

    add feature: negated regexes for postmaster filter
Merge branch 'reneeb_remove_URL_from_pdf' of https://github.com/reneeb/otrs
Use 3.3 support package.
Moved Phone Inbound and Outbound templates to Ticket Phone Call screen,  instead of Ticket Zoom.

Added new template type "Phone Call" for this templates.