Issue #49. Added ANTLR4 grammar for parsing Javadoc comments.
Issue #49. Added support of Javadoc comments. Extended API to create Javadoc Checks.
Issue #49. Added unit tests for generated parse trees of Javadoc comments
NonEmptyAtclauseDescriptionCheck #309
JavaDocTagСontinuationIndentation #308
SummaryJavaDocCheck #307 by Max Vetrenko
AtclauseOrderCheck #306
JavaDocParagraph #315
Fix build crash after manual merge. #317