Helper functions needed

[ibartomeus]

I added to my fork cleanSpecies() (depends on Taxize, which needs to be pre-loaded) and parseErrors().

In addition, I need to build two more functions:

credit() to give credit already formated for a bunch of id's and
search() as a wrapper for resorce() and query().

[ibartomeus]

Also would be good to have a query function filtering for created at: to be able to reproduce the database at point X in time.