Warned of the conflict w/ `scalacOptions := ...` in the README
Exclude code based on file name and not on class/package name

Closes #120.

Resolves #88.

Reverts and fixes #71.
Merge pull request #126 from LeifW/update_readme_about_scalac_options

Warned of the conflict w/ `scalacOptions := ...` in the README
Merge pull request #124 from michalrus/file-excludes

Exclude code based on file name and not on class/package name