#90 Pulses class introduced
#90 Query and MongoQuery
#90 Predicate added, tested
#90 test stabilized
#90 test fixed in WEB
#90 filter link for each tag in stand
#90 all tests fixed
Merge pull request #297 from yegor256/90

#297: pull request #90 Pulses, Query, Predicate classes added, tested with Mongo in integration tests