Tests fail on Windows;  Registered Global Namespace unreachable

Had to normalize all pathing to literal forward slashes rather than DIR_SEP in order to get tests to pass on Windows.

Added a test case to find the one file tied to the "global namespace" that's registered as '\\'.

Had to add new logic that searches a registered-as-'\\' global namespace, because current logic has the leading '\\' filtered out so early.