throw R-level errors for bad find_tags_motus command-line parameters

[jbrzusto]

e.g. rerunning a receiver with an invalid param override should generate an error, but doesn't. This makes it look as if data were processed and didn't lead to any detections, even though the data simply were not processed at all.

Two places this should happen:

• rerunReceiver.R and any other scripts
• ltFindTags() and sgFindTags()

Need something like

sanityCheckParams = function(progName, paramList) {
## check names and ranges of parameters for a program
...
}

It might make more sense to have find_tags_motus do this with an additional parameter --sanity-check, so that all the information about parameters is in one place.