ISPN-4950 Add ability to merge defaults into Metadata passed as param

* This is required in order to be able to apply default lifespan and
max idle settings configured globally for the cache.
* To do so, a new method has been added to builder that allows a
Metadata object to be merged with the builder instance.
* By making the default metadata builder implementation use objects
for primitives, it can easily distinguish between those settings
that have been set by the user versus the builder defaults.
'Release Script: update versions for 7.0.2-SNAPSHOT'
Update versions for 7.1.0-SNAPSHOT
ISPN-4939 Always include the clean goal as part of the lifecycle of the uberjar builds to avoid stale data
Remove references to old unused profiles in the documentation and the release script
ISPN-4939 fix missing uberjars from distribution zip and add back the extras profile to fix missing source artifacts
Configure event sender as an async Listener

* Ordering is only guaranteed as long as the async listener executor
is configured with 1 thread, which is the default.
* By using async listener, construction of the event and sending it
is taken out of the critical path of the Hot Rod client request.