A trait allowing to look for classpath entries in directories. It provides common logic for classes handling class and source files. It makes use of the fact that in the case of nested directories it's easy to find a file when we have a name of a package. It abstracts over the file representation to work with both JFile and AbstractFile.
Returns packages and classes (source or classfile) that are members of
inPackage string is a full package name, e.g., "scala.collection".
This is the main method uses to find classes, see class
rootMirror.rootLoader is created with
inPackage = "".