fix: Use configuration values to ignorePatterns.

[regseb]

Fix #3872

• Replace "/reports" by incrementalFiles in ignorePatterns (tempDirName was already in use).
• Describe tempDirName and incrementalFiles in documentation.

I didn't add htmlReporter.fileName and jsonReporter.fileName because I don't have access to these variables in the constructor.

[nicojs]

Thanks for picking this one up, and sorry it took me so long to respond. You should be able to add the output files from the HTML and JSON reporter quite easily; see my remark.

[nicojs]

This looks great! I love the additional test and changes there.