Updated identity check and VCF bugfix

* Identity check now looks in pipeline DB to decide whether to use Sequenom or Fluidigm plex manifest
* Identity.pm module converted into a Moose class
* Bugfix in VCF conversion for Fluidigm control samples
What is the logic behind this eval? All calls to equivalent are wrapped in one, I guess because that method croaks on error. The eval makes it not die. If this method should not die, don't call croak. If it should die, don't use eval.