[maven-release-plugin] copy for tag dnet-pace-core-2.1.0
lower casing moved to a final cleanup stage, added more distance functions
reduced default value
do not alter the fullname
configuration refactor: jsonization
added max.children configuration param
merged from branch configurationId
merged branch ProtoMapping
refactored normalization functions, updated cleanup behavior
fixed blacklist type
added toString
extended dedup configuration, including now blacklists and algorithm parameters
removed protocolbuffers dependency from dnet-pace-core, Builders and Proto specific tests moved in dnet-openaireplus-mapping-utils, adapted dnet-mapreduce-jobs
merged from branch 1.1.0