better messaging in sample apps when system properties are not defined
revisions from jeff's comments
Merge branch 'v2.2-documentation' of https://github.com/jeffswartz/Opentok-Java-SDK into jeffswartz-v2.2-documentation
change sessionId in prose to identifier, bring back lost Realeases section
Merge branch 'jeffswartz-v2.2-documentation' into modernization
Docs edit.