finbif v0.9.4

NEW FEATURES

• New undocumented variable "source" can be selected with
  finbif_occurrence.

MINOR IMPROVEMENTS

• Record pagination should now often require less queries of FinBIF
  server and be should be faster.

• FinBIF collections field names have been sanitised.

• When filtering records by "collection_id" a full URL ID can be used
  or a QName.

BUG FIXES

• Reading zero observation data downloads will now produce a zero row
  data.frame instead of triggering an error.