operatingsystem tests refactored on green

improved tests and corrected validation

Operatingsystem tests on green

architecture tests addded on green

fixes #167 - password will be updated each time to host is being edited

sessions are lazy loaded in rails 2.3, no need to declare them

Merge branch 'master' of git@github.com:ohadlevy/foreman

fixes #166 - query interface ignore state when using puppet classes instead of facts

fixes 163 - clean certificate only when a new build request starts

fixes #151 - add show host page
Added a nested link to hosts to lots of controllers