added switch to synonyms to dispath to different sources #383
fix in clasisifcation to use call. instead of .call in stop call
fix in children fxn to use call. instead of .call in stop all
removed unnecessary @method calls for s3 methods in downstream
removed unnecessary @method calls for s3 methods in upstream
added switch to downstream to dispatch to different sources #383
added helper fxn to stop on null param in zzz file
fixes to itis_downstream, was broken
fix to some itis low level fxns to coerce to data.frame
fixes to up and downsttream #383
use the helper check for db param fxn