Added experimental support for Plack/PSGI (see http://plackperl.org).

Squashed commit of the following:

commit 2afa3e476fba499169e5046a41adf5f5be8113af
Author: Martin Gruner <martin.gruner@otrs.com>
Date:   Tue Aug 13 10:55:55 2013 +0200

    Small improvements.

commit 89c3125ff50bf6f1ec3ff8f8ff8f4effed0bafb7
Merge: 35ba3dc b23c526
Author: Martin Gruner <martin.gruner@otrs.com>
Date:   Tue Aug 13 10:42:41 2013 +0200

    Merge branch 'master' into plack

    Conflicts:
    	COPYING-Third-Party

commit 35ba3dc2a4bcb25f7c109e4c8f6ca41b52b349a3
Author: Michiel Beijen <michiel.beijen@otrs.com>
Date:   Mon Aug 5 10:16:20 2013 +0200

    Added CGI::Emulate::PSGI so we only depend on plack.

commit 77cb358d852154a9672256dd164b609b4ff9825e
Author: Michiel Beijen <michiel.beijen@otrs.com>
Date:   Mon Aug 5 10:12:28 2013 +0200

    Moved Refresh mechanism to Module::Refresh so package install works properly as well.

commit 5b9999959880b121bb1ea8aa41925a9d466bd6ab
Author: Michiel Beijen <michiel.beijen@otrs.com>
Date:   Mon Aug 5 09:45:55 2013 +0200

    fallback to agent login if we could not determine handle

commit ff967a8c4121196cf0a18c50650e657b1b04cf35
Merge: 6620a93 c194076
Author: Michiel Beijen <michiel.beijen@otrs.com>
Date:   Mon Aug 5 09:32:56 2013 +0200

    Merge branch 'master' into plack

commit 6620a93ceb8f8030305c2030db21885f72f558d6
Merge: 877ba53 1fc7d8e
Author: Michiel Beijen <michiel.beijen@otrs.com>
Date:   Sat Jul 27 23:02:07 2013 +0200

    Merge branch 'master' into plack

commit 877ba53088b4a29dcb66771ebccaefd32c74c604
Author: Michiel Beijen <michiel.beijen@otrs.com>
Date:   Sat Jul 27 22:58:21 2013 +0200

    Added scripts for Plack based web server as a service on Win32

commit e861e86a8f586ba456f84fb25850e3a81a3a7373
Merge: 8e6b87f bfa7d94
Author: Michiel Beijen <michiel.beijen@otrs.com>
Date:   Tue Jul 23 09:33:46 2013 +0200

    Merge branch 'master' into plack

commit 8e6b87f337503b6777ca9a92d307147b87fd69c1
Author: Udo Bretz <udo.bretz@otrs.com>
Date:   Wed Jul 17 16:52:51 2013 +0200

    Improved TODO comment.

commit 4ccb9d831482745313a13c4eb8bfa2c05decbb21
Author: Udo Bretz <udo.bretz@otrs.com>
Date:   Wed Jul 17 16:17:07 2013 +0200

    First prove of concept implementation to always reload the config files to make the sysconfig screen work correctly.

commit 69bb783a4cf7daba0928d516bd8e4a49a9f46bf0
Author: Udo Bretz <udo.bretz@otrs.com>
Date:   Wed Jul 17 16:10:53 2013 +0200

    Added comma to improve code style.

commit 4ed35a805ec0465b5007cd9c7071d69e0d7e99f4
Author: Michiel Beijen <michiel.beijen@otrs.com>
Date:   Tue Jul 16 15:36:19 2013 +0200

    Added configuration for Apache as a reverse proxy for Plack

commit 0846bf26db1044be05603bc10b81298317fb6556
Author: Martin Gruner <martin.gruner@otrs.com>
Date:   Tue Jul 16 14:15:58 2013 +0200

    Improved plack tests.

commit c19dfbbf6d04342945d33ce69c49c72fbc24b65c
Author: Martin Gruner <martin.gruner@otrs.com>
Date:   Tue Jul 16 13:44:26 2013 +0200

    Added tests for plack.

commit 531d574ba0d620afbce8e3df48fa1361be5c90cd
Author: Martin Gruner <martin.gruner@otrs.com>
Date:   Tue Jul 16 11:28:36 2013 +0200

    Plack improvements.

commit cfc6b9a0afdb3d684ac819e8908c472be29e06b7
Author: Martin Gruner <martin.gruner@otrs.com>
Date:   Tue Jul 16 11:22:52 2013 +0200

    Plack improvements.

commit d9a95157dff9d6866b06e58f80e273c0c38e73a3
Author: Martin Gruner <martin.gruner@otrs.com>
Date:   Tue Jul 16 11:00:51 2013 +0200

    Some improvements on plack support.

commit 7b1981a6d1a46ab8ef1753dd5571801b605256a8
Author: Martin Gruner <martin.gruner@otrs.com>
Date:   Tue Jul 16 10:16:31 2013 +0200

    Improved plack support.

commit 7d881a99a563c03a5a563a3a1d6b2c6065c9ad5d
Author: Martin Gruner <martin.gruner@otrs.com>
Date:   Mon Jul 15 15:31:56 2013 +0200

    Progress on plack.

commit 33c273a3d929026d77d4aa83fab92ff287751385
Author: Martin Gruner <martin.gruner@otrs.com>
Date:   Mon Jul 15 15:17:54 2013 +0200

    Progress on plack prototype.

commit f5564cf8e7fa178f317ea24b42c1587da643ab47
Author: Martin Gruner <martin.gruner@otrs.com>
Date:   Mon Jul 15 14:47:28 2013 +0200

    First stab at plack prototype.