4.0.0-RC2

• #39 create one SonarQube check per Code Smell type
• #43 add missing UTs
• #48 migrate to sonar-java-plugin 4.4 API
• #49 move to java-checks-testkit
• #50 Adapt Metrics Type (Long->Integer)
• #51 Migrate from SonarPlugin to Plugin
• #52 Fix log levels
• #53 Fix debt metric computation tests
• #54 Add new smell types
• #55 Fix displayed name of SMELL_DEBT metric
• #56 Move documentation to wiki pages
• overall code quality improvement