* Re-added missing server side span
with this change
- HandlerInterceptor is responsible for wrapping requests in spans
- added Sring Data REST instrumentation
- added Zuul instrumentation
- it will not wrap error controller related requests with spans
- tests have been changed to ensure that ALWAYS there is at least one span on the server side (that way it will show up in Zipkin)
- "fallback" mechanism has been added that if a HandlerInterceptor hasn't been used then we are forcing creation of a Span at the server side
fixes#321
(cherry picked from commit 4f1ef52e6c)
bfce279d52