Razor hlt filters for run2 development in 72X

* Modified HLT razor filter to allow consuming PF MET 
* HLT razor filter now inherits from HLT Filter class to allow saving online trigger quantities
* More details on the razor triggers for Run 2 can be found at the latest TSG SUSY report https://indico.cern.ch/event/339419/contribution/6/material/slides/0.pdf and SUSY Trigger report https://indico.cern.ch/event/349250/contribution/2/material/slides/0.pdf
@vlimant 
```
filterproduct.addCollectionTag(edm::InputTag( *moduleLabel()));
```
should only be done if saveTags() is true ! Please add the if clause,
ie, something like
```
 if (saveTags()) filterproduct.addCollectionTag(edm::InputTag( *moduleLabel()));
```
(in both PRs, ie, for 72X and 73X)