Support ISO 19115-3 metadata standard (through geometa 0.9)

[eblondel]

geometa 0.9 has been accepted for publication on CRAN. This version supports the ISO 19115-3 standard. Adjustments are required to make sure the OGC CSW Client operated by ows4R, and its methods GetRecordById and GetRecords can detect ISO 19115-3 metadata , switch to ISO 19115-3 and read metadata into geometa objects.

See eblondel/geometa#181