Fix bug in geometry loading in geometry comparison and use Configuration...

.../Geometry package instead of Configuration/StandardSequences in Alignment/OfflineValidation.
@ianna for my education: [Configuration/Geometry/python/GeometryIdeal_cff.py](https://github.com/cms-sw/cmssw/blob/CMSSW_7_3_X/Configuration/Geometry/python/GeometryIdeal_cff.py) loads the SIM geometry from the ideal scenario as in XML release files, while RECO one is loaded from GT.
Is this correct?