Merge branch 'feature/criteria' - closes #2

Squashed commit of the following:

commit 09f4de5211ee87cfccd4df5431cfec552c04528e
Author: Andreas Lutro <anlutro@gmail.com>
Date:   Thu Jun 19 14:27:09 2014 +0200

    add some docblocks

commit d02b4b4a5488e046d4c10c845c8e91382bc164f3
Author: Andreas Lutro <anlutro@gmail.com>
Date:   Thu Jun 19 14:10:41 2014 +0200

    setupDefaultCritera() disappeared somehow

commit 6d376d697ba623f12063cccaaa194ea0f1b96641
Author: Andreas Lutro <anlutro@gmail.com>
Date:   Thu Jun 19 13:50:02 2014 +0200

    make addDefaultCriteria protected

commit da6591322b615478a4782cea1f62e85e946aa498
Author: Andreas Lutro <anlutro@gmail.com>
Date:   Thu Jun 19 13:48:07 2014 +0200

    simplify some methods

commit 1956b37999640337e8cd2d343d987484312eae2f
Merge: 218eba5 789fc25
Author: Andreas Lutro <anlutro@gmail.com>
Date:   Thu Jun 19 13:39:21 2014 +0200

    Merge branch 'master' into feature/criteria

    Conflicts:
    	src/AbstractRepository.php

commit 218eba54981bdaeb2d3539c8d91cf6e0aaeb8605
Author: Andreas Lutro <anlutro@gmail.com>
Date:   Thu Jun 19 13:26:18 2014 +0200

    implement default criteria

commit 26594083e11372dda90a52d4fb44cc97fba22332
Author: Andreas Lutro <anlutro@gmail.com>
Date:   Thu Jun 19 11:38:56 2014 +0200

    work on criteria