Generalized met workflow

met.workflow.gen.R can be used for 
- downloading raw NARR
- converting to raw NARR to CF 
- Rechunk/Permuting for faster extraction times
- extracting for specific sites
- met2model.SIPNET (ED2 should also be working)

parameters are set in met.workflow.params.R
dbparms seems to be passed as an argument, but doesn't appear to be used anywhere in the function since the con is also passed. Do we need dbparms somewhere that I'm missing?