Added the 'csvw' prefix to the RDFa initial context
In accordance with the way the RDFa initial context is defined, the list of predefined prefixes has been extended by adding '
csvw'. The corresponding vocabulary URI is
http://www.w3.org/ns/csvw#, and it stands for the metadata vocabulary for tabular data, like CSV or TSV, which was published as a Recommendation at the very end of 2015.
Reminder: the RDFa initial context provides a number of prefixes and a number of prefix-less properties that RDFa processors should recognize with the user being required to add those via a