Inverse the match verification in ContentHostingContentProducer

An event match if the action ISN'T unknown
Enforce the third person usage in the javadoc
Use the same name convention for every maven project
Move solr configuration in the conf folder

This way it's possible to use org/sakaiproject/search/solr/conf as
SOLR_HOME
Rename solr.search.data.dir to the default solr.data.dir
Use NRT directory with solr 4.1
Reposition abortOnConfigurationError
Use the default configuration for the select path
Replace deprecated XmlUpdateRequestHandler with UpdateRequestHandler
Enable the high-performance update handler
Introduce the _version_ field in solr
Use the default definition for the fields date and string
indexdate isn't multivalued by default, no need to insist