DEMO: Uncomment code that tests content-length values in tests (core-server:HeadTest, e2e:ContentLengthTest).
With MBW.getSize() ignored in JAX-RS 2.0, we may want to implement a way that would let us compute the Content-Length value for messages of up to certain size. We could do this by defining a configurable-size buffer for outbound entities that would try to buffer whole entity and compute the actual Content-Length value that would be then set in the headers before flushing the buffered entity. Should the buffer overrun, it would resume to serializing the entity without computing the C-L value.
add client side request tests