Remove quote stripping code.

I'm guessing it was added due to a misunderstanding of how shell
quoting works.  When you invoke

   stow --ignore=".#.*" ...

the shell strips out the quotes before the Perl process ever sees them.
I can't imagine any sensible scenario in which you would need to invoke

   stow --ignore='"foo"'

but if the user has a filename containing quotes at the beginning and
end, they can now choose to ignore it (prior to this patch, they couldn't).

t/stow.t

@@ -7,7 +7,7 @@
 use strict;
 use warnings;
 
-use Test::More tests => 10;
+use Test::More tests => 9;
 
 use testutil;
 
@@ -71,23 +71,12 @@ local @ARGV = (
 ($options, $pkgs_to_delete, $pkgs_to_stow) = process_options();
 is_deeply($options->{override}, [qr(\Aman), qr(\Ainfo)] => 'override man and info');
 
-#
-# Check stripping any matched quotes
-#
-local @ARGV = (
-    "--override='man'",
-    '--override="info"',
-    'dummy'
-);
-($options, $pkgs_to_delete, $pkgs_to_stow) = process_options();
-is_deeply($options->{override}, [qr(\Aman), qr(\Ainfo)] => 'strip shell quoting');
-
 #
 # Check setting ignored paths
 #
 local @ARGV = (
-    '--ignore="~"',
-    '--ignore="\.#.*"',
+    '--ignore=~',
+    '--ignore=\.#.*',
     'dummy'
 );
 ($options, $pkgs_to_delete, $pkgs_to_stow) = process_options();