Simple repository and specification patterns
Observer and Observer with Mediator Patterns
Merge branch 'master' into NotingImportant
little tweaks
reimplementing some tweaks

Like I see, some things were implemented not clearly enough. I recreated
few lines and added proper comments. Good idea implementing
ChangeMediator this way. Its something i looked for.
Thanks for Resharper cleaning :P.
Merge pull request #5 from bobslej/NotingImportant

Noting important