Modified stratData and rvcData so warning not output when more than on strata used in strata argument
Previously if strata or years were specified by user and were longer than length 1, a warning would be output because the conditional in the if statement would only evaluate the first element. Now it evaluates the conditional against the entire list. This modification has no functional differences, but the warning was a bit annoying.
Added documentation for lenFreq and domin and stratum density/occurrence wrapper functions