* Do not apply content-type header if no request body
* Set content-type header if there are form params
* Add tests
* Run update script
* Regenerated sample clients
* Closes#5863
The "dateLibrary" option for java, sadly, sets a mustache value "java8". This change updates this so that "java" in the mustache
libraries means what it should mean - use all java8 classes. In this case, there's no need for the third party Base64 library
as java8's JDK has this built in. In my view, the "dateLibrary" should be deprecated but that should be a separate PR.
* Closes#5954
built and ran tests/samples
* update dep for java jersey1, jersey2
* update sbt dependency for jersey2
* update dep for java okhttp-gson, resteasy, resttemplate
* update dep for java retrofit 1.x, 2.x
* update java petstore samples
