VIF and HFG implementation

The check_design() method is fleshed out. I wasn't sure if every feat
directory would have the same number of evtitle and convolve keys in the
fsf dictionary. From what I gathered from the example in HFG checking, 
if evtitle<n> had a mot parameter as a value then convolve<n> must be 0
for all n 1 thru 10. Also, I wasn't sure about what other warnings could be possible.