Add XML-style license header format

[gdude2002]

This PR makes the following changes:

• Add support for Kotlin to the build environment, in explicit API mode for readability
• Add support for XML-style comments, including a default configuration
  • This is heavily commented as I know Aurora isn't too familiar with Kotlin
  • Includes unit tests (yes, that really is how we write those in Kotlin)
• Add some extra default file-types for C-style header comments, specifically for common web languages and stylesheet formats
• Bump version to 1.2.0
• Update .gitattributes to fix functional tests that failed on Windows due to line endings

[LambdAurora]

Amazing, thank you again for your contribution!