Merged the search into the master. Still working on the notification on item change.
notification on item creation works fine.

Squashed commit of the following:

commit bc9fde4cffc857060024d79b5bd00339f054f711
Author: Kenneth Radunz <kenneth.radunz@web.de>
Date:   Tue Oct 23 22:15:36 2012 +0200

    now subscriptions are working fine. Adding and deleting works.
    A user gets a mail if a fitting item was created still hanging on the changed...

commit b8ae37ad079fc8f343ee5cb258258425b67907c7
Author: Mei Ling Wong <mei.ling@students.unibe.ch>
Date:   Tue Oct 23 20:44:43 2012 +0200

    fixed search function but subscribe still is not working.

commit 8fb48933922560ec761243b8f214aa85fb2c1e95
Merge: 524dcf0 aa42c6e
Author: Mei Ling Wong <mei.ling@students.unibe.ch>
Date:   Tue Oct 23 19:36:10 2012 +0200

    Merge branch 'issue#18Search' of github.com:ese-unibe-ch/ese2012-team2 into mw_work

commit 524dcf016cf92d40428f0f4f0246e15dcadf6f33
Merge: 314b480 77eadbf
Author: Mei Ling Wong <mei.ling@students.unibe.ch>
Date:   Tue Oct 23 19:35:35 2012 +0200

    Merge branch 'work_br' of github.com:ese-unibe-ch/ese2012-team2 into mw_work

commit aa42c6e7566f70915d98db5bb6d1d897fdf95f63
Author: Kenneth Radunz <kenneth.radunz@web.de>
Date:   Tue Oct 23 17:22:27 2012 +0200

    added the event handling of the SearchRequest

commit 77eadbf3e0de924cc9e6f225706a9f4a637a0fa8
Author: flaviawili <flaviawili@msn.com>
Date:   Tue Oct 23 16:19:42 2012 +0200

    Implemented all search function, but still not working yet

commit 91262997bc4d583bcf7142fd6d3658f33b0f0c9b
Merge: d1b7d3b 27ebcc1
Author: flaviawili <flaviawili@msn.com>
Date:   Tue Oct 23 15:06:55 2012 +0200

    Merge branch 'issue#18Search' of https://github.com/ese-unibe-ch/ese2012-team2 into work_br

commit d1b7d3b50b037b056ca90bdba49b9f2a89380761
Author: flaviawili <flaviawili@msn.com>
Date:   Tue Oct 23 15:06:28 2012 +0200

    Implemented search function in controllers, view subscribed search requests still missing

commit 27ebcc11cdd15b163ddbf5d1989f48b8d53c3b25
Author: Arun Sittampalam <arun@sittampalam.ch>
Date:   Tue Oct 23 14:48:10 2012 +0200

    SearchRequest is ignoring upper/lower case now(#18)

commit 0fc17a4fedce413e475086cc94c695e5d3a2b919
Author: Arun Sittampalam <arun@sittampalam.ch>
Date:   Tue Oct 23 14:39:28 2012 +0200

    Added an id to the SearchRequest model (#18)
    And had to restructure some things to do so.

commit 3d1d4841f55981a6b2be46a14ef4698754ab0d10
Author: Mei Ling Wong <mei.ling@students.unibe.ch>
Date:   Mon Oct 22 23:00:21 2012 +0200

    implemented search button in index and a search view.

commit 67b3820f83ce4a36c12622a8173b4e08ef7c25e4
Merge: d1bc91e 461cfa3
Author: Mei Ling Wong <mei.ling@students.unibe.ch>
Date:   Mon Oct 22 21:01:09 2012 +0200

    Merge branch 'issue#18Search' of github.com:ese-unibe-ch/ese2012-team2 into work_br

    Conflicts:
    	trade/app/models/data_overlay.rb
    	trade/test/data_overlay_test.rb

commit 461cfa3c56dd9e54bdd52e653e3ec987493e3912
Author: Arun Sittampalam <arun@sittampalam.ch>
Date:   Mon Oct 22 19:04:42 2012 +0200

    Solved point 1 and 2 of issue #18.
    Wrote tests for the new model. But commented out all the old tests which
    are partially failing, because the other group is (hopefully) working on
    fixing these.

commit d1bc91e7c46713e3a4b47dc10bd0a8665fc2ab2e
Author: Mei Ling Wong <mei.ling@students.unibe.ch>
Date:   Sat Oct 20 23:07:04 2012 +0200

    added search form, but not implemented anything specific in controllers yet

commit 5cb8394fcd1402a223300b83a9ebc4da81f1e763
Merge: 08e3602 aa24258
Author: Mei Ling Wong <mei.ling@students.unibe.ch>
Date:   Sat Oct 20 21:40:01 2012 +0200

    Merge branch 'issue#18Search' of github.com:ese-unibe-ch/ese2012-team2 into work_br

commit aa2425860a14c1d79a0019e9bafcb4df7ef4f62c
Author: Kenneth Radunz <kenneth.radunz@web.de>
Date:   Wed Oct 17 18:23:33 2012 +0100

    added a BaseEventClass and a ItemUpdateEvent. Not sure if it works as I want it ;)