Added Event entity
Added Location entity
Added City entity
Added Organizer entity
Added M2O mapping between Event and Location
Added M2O mapping between Event and Organizer
Added M2O mapping between Location and City
Created Filter bundle
Added Keyword entity
Added KeywordNorm entity
Added Tag entity
Added 1:1 mapping between Keyword and KeywordNorm
Added M2M mapping between KeywordNorm and Tag
Added M2M mapping between Event and Tag
Generated getters and setters for all entities