clojure.tools.namespace.move/move-ns requires that the caller provide both 1) the directory containing the file to be moved; and 2) the collection of directories containing all source files to be updated with the new name. This is redundant.
Instead, we can search for the file in all source directories, move it within the same root directory, then update all files in all directories.
In addition, with java.classpath in TNS-36, the set of directories to search can default to directories on the classpath. This will be much more convenient for REPL use.
This change can be made without breaking older arities of move-ns.