Add ClassLoadingUtil.getDirClassWasLoadedFrom

Adding to this library so that it can be used by both the http-tests maven project inside asset-bank and src-test inside asset-bank. Currently similar code has been copied and pasted between these directories.

This is to allow AB-1811 to be fixed without even more code duplication.
Merge pull request #1 from brightinteractive/get_dir_class_was_loaded_from

Add ClassLoadingUtil.getDirClassWasLoadedFrom