[FEATURE #61726528] inventory export for all pools

Squashed commit of the following:

commit 06df142232d06f40fda60f95bc09a8f27336d987
Author: Matus Kmit <matus.kmit@zhdk.ch>
Date:   Thu Dec 12 12:20:29 2013 +0100

    [DOMINA] updated feature_tasks.yml

commit e85bafcaa0f10f0695dcf93bbd95d01909a7be41
Author: Matus Kmit <matus.kmit@zhdk.ch>
Date:   Thu Dec 12 11:14:46 2013 +0100

    further optimize speed for global export

commit 20c69ee521bdef62b601046a0a0e74f9c349acb4
Author: Matus Kmit <matus.kmit@zhdk.ch>
Date:   Thu Dec 12 10:01:51 2013 +0100

    handle empty options correctly

commit 5eb11e3997fb31b8f9c7bd6b95785eafbc384d87
Author: Matus Kmit <matus.kmit@zhdk.ch>
Date:   Thu Dec 12 10:01:05 2013 +0100

    test (only presence of link)

commit 5a74a66806359a11f15228d8cbe005b5889b456b
Author: Matus Kmit <matus.kmit@zhdk.ch>
Date:   Wed Dec 11 17:30:56 2013 +0100

    remove rake task implementation

commit e662aacad554bcd64e669698d6c25dac74a03ec1
Author: Matus Kmit <matus.kmit@zhdk.ch>
Date:   Wed Dec 11 16:09:09 2013 +0100

    fixed path helper

commit 15831d14fde412f0b95268ed38e4d7e2102eb0ec
Author: Matus Kmit <matus.kmit@zhdk.ch>
Date:   Wed Dec 11 16:05:26 2013 +0100

    Open CSV export in new tab

commit a79a0cc15707fb4463b9002fe220faa46eefeea9
Author: Matus Kmit <matus.kmit@zhdk.ch>
Date:   Wed Dec 11 15:44:18 2013 +0100

    eager loading associations on item -> speeding up export

commit 25a7eaa321bdd1b2c67aa5a7177d1e8407d95330
Author: Matus Kmit <matus.kmit@zhdk.ch>
Date:   Wed Dec 11 15:43:19 2013 +0100

    make global accessible via UI

commit baa46b814e66afa1a0422daa904cedad7d3f39b7
Author: Matus Kmit <matus.kmit@zhdk.ch>
Date:   Wed Dec 11 15:42:24 2013 +0100

    improve rake task

commit a9ad3d285ee5f3ad0affcc75d60255c7eb5928be
Author: Matus Kmit <matus.kmit@zhdk.ch>
Date:   Tue Dec 10 16:54:40 2013 +0100

    finish implementation

commit 44377b7d80132edbfd9191020597fe62a0a8aa47
Author: Matus Kmit <matus.kmit@zhdk.ch>
Date:   Fri Dec 6 16:03:26 2013 +0100

    first working draft