New ignoreUnusedPathVariables property added to ApiDocumentationController, true by default.
Sometimes there are path variables which are not used in method directly.
For instance, we have /user/pets/{petId}, but method doesn't have @PathVariable petId because
it's used for MethodArgumentResolver in upper level, but we still need this fields
Such fields are not documented by Swagger by default.

Minor changes:
1. Utility methods moved to DocumentationUtils
2. Default Java version(1.5) added to pom.xml