Refactored check-webkit-style's ProcessorOptions class into two

Refactored check-webkit-style's ProcessorOptions class into two
classes. This revision contains no new functionality.

Reviewed by Shinichiro Hamaji.

https://bugs.webkit.org/show_bug.cgi?id=34674

Divided the ProcessorOptions class into a CommandOptionValues
class (the result of parsing the command-line options) and
a StyleCheckerConfiguration class (which configures the main
StyleChecker).

* Scripts/check-webkit-style:
  - Updated main() to convert the parsed command option values
    to a StyleCheckConfiguration instance prior to constructing
    a StyleChecker.

* Scripts/webkitpy/style/checker.py:
  - Added check_webkit_style_configuration() to convert a
    CommandOptionValues instance into a StyleCheckerConfiguration
    instance.
  - Renamed the ProcessorOptions class to CommandOptionValues.
  - In the CommandOptionValues class--
    - Replaced the filter_configuration attribute with the
      simpler filter_rules attribute.
    - Removed the max_reports_per_error attribute.
    - Moved the is_reportable() method to the new
      StyleCheckerConfiguration class.
  - Removed the base_filter_rules attribute from the
    DefaultCommandOptionValues class.
  - In the ArgumentParser class--
    - Added base_filter_rules to the constructor.
    - Changed the parse() method to return a CommandOptionValues
      instance instead of a ProcessorOptions instance.
  - Created a StyleCheckerConfiguration class.
    - Added the data attributes max_reports_per_category,
      stderr_write, and verbosity.
    - Added is_reportable() (moved from the ProcessorOptions
      class) and write_style_error() (moved from the
      DefaultStyleErrorHandler class).
  - In the StyleChecker class--
    - Replaced the ProcessorOptions options attribute with the
      StyleCheckerConfiguration _configuration attribute.
    - Removed the _stderr_write attribute.

* Scripts/webkitpy/style/checker_unittest.py:
  - Updated the existing unit test classes as necessary.
  - Added a StyleCheckerConfigurationTest class.

* Scripts/webkitpy/style/error_handlers.py:
  - Updated the DefaultStyleErrorHandler class to accept a
    StyleCheckerConfiguration instance instead of a ProcessorOptions
    instance and an stderr_write method.

* Scripts/webkitpy/style/error_handlers_unittest.py:
  - Updated the unit test classes as necessary.

* Scripts/webkitpy/style/filter.py:
  - Addressed the FIXME in the FilterConfiguration class to change
    the user_rules attribute to _user_rules (since it is now
    accessed only internally).

* Scripts/webkitpy/style/filter_unittest.py:
  - Updated to reflect the change from user_rules to _user_rules.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@54934 268f45cc-cd09-0410-ab3c-d52691b4dbfc