[maven-release-plugin] copy for tag 0.31.0-RC2 

Mention the 0.30 compatibility package in the README. (opentracing#236) * Mention the 0.30 compatibility package in the README.

[maven-release-plugin] copy for tag 0.30.0 

Mock baggage (opentracing#129) * Propagate mock baggage items * Restore expanded imports * Fix order of parameters in assertions * Remove special case for no baggage * Minor formatting to assist rebase * Remove unnecessary imports * Add prefix to baggage item keys

[maven-release-plugin] copy for tag 0.30.0.RC3 

Change copyright comment in java files from /** */ style to /* */. (o… …pentracing#143)

[maven-release-plugin] copy for tag 0.30.0.RC2 

Adjust regexp escaping 

Use the Spring format 

Force all years to 2017