Changed filename/path filtering functions return types from boolean to filtered lists, which allows to apply the filters at an earlier stage, at which we can hopefully get rid of hidden directory ancestors.
Fixed filter processing for hidden files/directories, fixed some more variable namespace ambiguities.
Clean up debugging stuff. Now, there is a TypeError: unhashable type: 'list' when using -a flag
No idea whats going on, so killing time renaming functions and paraphrasing expressions