New DownloadSingle function, with error checking and documentation
Merge pull request #25 from amarillion/amarillion

New DownloadSingle function, with error checking and documentation
Fix typo in two identifiers.org values
define identifiers.org values for mesh, go, bind, cas, cygd, dbsnp, geneid, homologene, mgi, ndc, pubchem, refseq, unists, unigene, zfin
Merge pull request #26 from amarillion/002-identifiers.org-additions

002 identifiers.org additions
Merge remote-tracking branch 'upstream/bio2rdfapi' into bio2rdfapi

Conflicts:
	ns.php
added trigger_error when creating directories