Recognize difference between comments and code changes

[rnveach]

Example commit: checkstyle/checkstyle@2a56547

Lots of no-inspection comments were added, only a few actual code changes but regression was still run on all modules in commit.

Generated configuration:

  <module name="TreeWalker">
    <module name="IndentationCheck"/>
    <module name="CyclomaticComplexityCheck"/>
  </module>
  <module name="UniquePropertiesCheck"/>

Only CyclomaticComplexityCheck had actual code changes and needs regression.