Updated 2.6 beta1 tag

Second alpha for Refine 2.6

First alpha release of 2.6. This is primarily intended for developer …

…testing.

Vocabulary force import

Updated OpenRefine and crowdsourcing extension

Replaced name in run() target of refine

Error handling in crowdsourcing extension

Minor changes for rdf extension

Tagging 2.5 for release.

Tagging 2.5 rc3.