Load Cache from a String (rather than a File)

[cverges-medallia]

When using dnsjava to support unit testing, it's helpful to be able to load a Cache from a file reference that may be in a classpath or an in-memory dynamically created string. The current Cache(String) constructor takes in a filename reference as a String (rather than a File or Path). It would be nice if Cache(String) or even Cache(InputStream) takes in the contents of a zone file and we introduce new Cache(File) or Cache(Path) alternatives for loading an actual zone file from such a reference.

[ibauersachs]

Hey, thanks for the notice. Would you mind creating a pull request to introduce the suggested Cache(InputStream) constructor?