Configure - neater looking add() and add_before()

They now default to " " as separator, but that can be overridden by
having a hash with parameters as last argument.  The only currently
recognised parameter is `separator'.

The special separator `undef' will force the result to become a list
rather than a concatenated string.

Reviewed-by: Andy Polyakov <appro@openssl.org>

Configure

diff --git a/Configure b/Configure
index b6c8d8c..ad20bf6 100755
--- a/Configure
+++ b/Configure
@@ -1970,12 +1970,20 @@
     }
 }
 sub add_before {
-    my $separator = shift;
+    my $separator = " ";
+    if (ref($_[$#_]) eq "HASH") {
+        my $opts = pop;
+        $separator = $opts->{separator};
+    }
     my @x = @_;
     sub { _add($separator, @x, @_) };
 }
 sub add {
-    my $separator = shift;
+    my $separator = " ";
+    if (ref($_[$#_]) eq "HASH") {
+        my $opts = pop;
+        $separator = $opts->{separator};
+    }
     my @x = @_;
     sub { _add($separator, @_, @x) };
 }