Checkstyle 8.0

[Roman Ivanov]

Checkstyle 8.0 - http://checkstyle.sourceforge.net/releasenotes.html#Release_8.0

Breaking backward compatibility:

  api changes: make getAcceptableTokens/getRequiredTokens/getDefaultTokens methods as abstract in Check.java
  deprecate Checker.setClassloader , replace with Checker.setClassLoader
  Remove deprecated Check class
  CheckstyleAntTask: substitude setConfig(File) with setConfig(String)
  remove deprecated getFilename menthod from FileContents
  rename STMT in BlockOption class to STATEMENT
  Remove unnecessary text from Javadoc tokens
  Cache conflict between Maven/Ant and Eclipse/CLI run

New:

  MethodCountCheck: add ANNOTATION_DEF to toknes to avoid NPE

Bug fixes:

  some messages are still hardcoded in english
  MethodCountCheck: wrong counting with nested interface definition
  Indentation: custom annotation not checked
  Javadoc is not parsed correctly in files with only CR newlines
  CLI Javadoc tree printing does not check placement of Javadoc
  Javadoc parser: custom tags content should not be parsed as HTML

Notes:

  pmd: fix all the remained
  Localized UTs are not stable on Travis
  Add since version to Checkstyle documentation
  Fix PMD violations for test code in Checkstyle
  Split and Organize Checkstyle inputs by Test for checks in 'indentation' package
  Use Spotbugs tool in our build process
  pmd: enable validation on IT java sources
  upgrade maven-pmd-plugin to version 3.8
  Split and Organize Checkstyle inputs by Test for checks in imports package
  Refactor Javadoc AST Tests
  pmd: fix JUnitAssertionsShouldIncludeMessage violations in test classes
  pmd: fix TestClassWithoutTestCases violations in test classes
  pmd: fix UselessOverridingMethod violations in test classes 
  pitest: increase mutation coverage for pitest-checkstyle-utils profile to 100%
  refactoring: remove 'final' modifier from all arguments of method/c-tor at ImportControlCheck and around
  pmd: fix AppendCharacterWithChar violations in test classes
  pmd: fix InsufficientStringBufferDeclaration violations in test classes
  pmd: fix UncommentedEmptyMethodBody violations in test classes
  pmd: fix LoggerIsNotStaticFinal violations in test classes
  pmd: fix NcssMethodCount violations in test classes
  pmd: fix JUnit4TestShouldUseTestAnnotation violations in test classes
  pmd: fix ConfusingTernary violations in test classes
  pmd: fix CommentDefaultAccessModifier violations in test classes
  pmd: fix CheckstyleCustomShortVariable violations in test classes
  pitest: increase mutation coverage for pitest-checkstyle-common profile to 100%
  pitest: increase mutation coverage for pitest-checkstyle-api profile to 100%
  pitest: increase mutation coverage for pitest-checkstyle-tree-walker profile to 100%
  Split and Organize Checkstyle inputs by Test for checks in header package