clean up some spacing
allow export of scrubber_add_scrubber and scrubber_remove_scrubber
remove a bad croak when overriding a method
change the system to properly ignore empty scrubber values

# Please enter the commit message for your changes. Lines starting
# with '#' will be ignored, and an empty message aborts the commit.
# Explicit paths specified without -i nor -o; assuming --only paths...
#
# Committer: Jason Terry <jterry@jterry-laptop.(none)>
#
# On branch master
# Changes to be committed:
#   (use "git reset HEAD <file>..." to unstage)
#
#	modified:   Scrubber.pm
#
# Untracked files:
#   (use "git add <file>..." to include in what will be committed)
#
#	MYMETA.json
#	MYMETA.yml
#	Makefile.old
#	package.t
