[CANCELLED] [VOTE] Release taverna-language-0.15.1-incubating-RC4 and taverna-osgi-0.2.1-incubating-RC4

[Stian Soiland-Reyes]

Thanks to all who tested this release candidate and provided feedback in
the DISCUSS thread?!

I'm sorry to be CANCELLING this vote, as TAVERNA-918 still prevented build
on Windows. Thanks to Ian, Menaka, Dmitry and Andy for quickly figuring out
a solution, so I'll start immediately to prepare a RC5.