Add info about OpenBSD support to README.md and metadata.json
Add a note about OpenBSD java_version fact to README.markdown.
Fixup wording on context in one of the java patch level regression tests.
No mentioning of OpenBSD in metdata.json
Cleanup wording of context as suggested by @elyscape
update contexts as suggested by @elyscape
Adapted from the many found on Github, simply runs `java -version` and strips the results. From what I can find there aren't many edge cases for the result `java -version 2>&1` could return, so this should be fairly compatible.