Make Config's ctor accept strings as values for glob_paths, as
opposed to lists. This covers the canonical case of one configuration
file being passed.
Signed-off-by: Jan Lindemann <jan@janware.com>
Initializing Config from a StringTree object doesn't stop it from
looking for config files to read. Stop that.
Signed-off-by: Jan Lindemann <jan@janware.com>