Upgrade to Checkstyle 7.8.1

Release 7.8.1

Bug fixes:

    problem with usage of third-party Check libraries and checkstyle 7.8. Author: rnveach, Roman Ivanov #4387

Notes:

    pitest: increase mutation coverage for pitest-check-annotation profile to 100%. Author: vasilyeva #4402
    pitest: create profile for non-checks code . Author: vasilyeva #4367

Release 7.8

New:

    ImportControl: new strategyOnMismatch property to xml file structure. Author: Tima #4274
    NoWhitespaceAfter: add support for method reference operator (new Acceptable token). Author: Dmytro Kytsmen #3950
    LocalFinalVariableName: not validating try-with-resource variables (new Acceptable token). Author: vasilyeva #3348
    IllegalImport: new property illegalClasses to let blacklist certain classes import. Author: Tima #3449
    ExplicitInitialization: new property 'onlyObjectReferences'. Author: Subbu Dantu #2399

Bug fixes:

    Javadoc parser: Package names should permit digits in their name. Author: Piyush Sharma #4349
    Expand exception violation when haltOnException is off. Author: rnveach #4350
    CacheFile: violation on external resource will invalidate entire cache even if no changes are made. Author: rnveach #4101
    RequireThis: False positive for lambda parameters. Author: Piyush Sharma #4207

Notes:

    bump version for sevnu-checkstyle. Author: Roman Ivanov
    publish all dtd schemas to sourceforge site automatically. Author: Andrei Selkin, Roman Ivanov #4341
    Use reflection to load Checks base on checkstyle_packages.xml. Author: Luolc #3607
    upgrade maven-pmd-plugin to version 3.8. Author: Dmytro Kytsmen #4342
    Split and Organize Checkstyle inputs by Test for checks in coding package. Author: slava ganyaev, Dmytro Kytsmen #4165
    ImportControl: blacklist mode. Author: Tima #3451
    Localized UTs are not stable on Travis. Author: Roman Ivanov #4316
    moved more variables inside if blocks to reduce execution. Author: rnveach #4343
    spelling: Improve grammar of usage.distance.extend. Author: Jaron Thatcher
    Split and Organize Checkstyle inputs by Test for checks in annotation package. Author: Dmytro Kytsmen #4313
    Revert "Revert "config: bump maven-surefire-xxxxxx to 2.20" due to unstable locale UTs #4316". Author: Roman Ivanov
    moved variables inside if blocks to reduce execution time. Author: rnveach #4328
    doc: add link to contributing instructions to CONTRIBUTING.md. Author: Nathan Naze
    Split and Organize Checkstyle inputs by Test for checks in design package. Author: Dmytro Kytsmen #4314
    Split and Organize Checkstyle inputs by Test. Author: Dmytro Kytsmen #3891
    Wercker CI is unstable while cloning repositories. Author: Roman Ivanov #4329
    Revert "config: bump maven-surefire-xxxxxx to 2.20" due to unstable locale UTs #4316. Author: Roman Ivanov
    Split and Organize Checkstyle inputs by Test for PackageName. Author: Dmytro Kytsmen #4172
    Split and Organize Checkstyle inputs by Test for MemberName. Author: Dmytro Kytsmen #4151
    Split and Organize Checkstyle inputs by Test for MethodName. Author: Dmytro Kytsmen #4158
    move all dtd schemas to sourceforge site. Author: Andrei Selkin #1571