1.0.4

This bug-fix release addresses several small issues.
Users of Californium 1.0.x should be able to upgrade by simply replacing the 1.0.x artifacts with the corresponding 1.0.4 artifacts.

Changelog:
#43 californium-osgi bundle artifact does not pass jarsigner verification
#36 Block2 request does not seem to notify CoapHandler#onError if exchange stucks on non-first request.

Build artifacts:
on Maven Central
on Eclipse Repo

NB Due to the Maven Central staging process it might take some time for the artifacts to be available from Maven Central.