Added Node#remove.

This method can be used to remove individual nodes without first having to
retrieve the NodeSet they are stored in.

lib/oga/xml/node.rb

@@ -130,6 +130,15 @@ module Oga
         return node
       end
 
+      ##
+      # Removes the current node from the owning node set.
+      #
+      # @return [Oga::XML::Node]
+      #
+      def remove
+        return node_set.delete(self) if node_set
+      end
+
       ##
       # Generates the inspect value for the current node. Sub classes can
       # overwrite the {#extra_inspect_data} method to customize the output

spec/oga/xml/node_spec.rb

@@ -154,4 +154,24 @@ describe Oga::XML::Node do
       @n4.root_node.should == @n3
     end
   end
+
+  context '#remove' do
+    before do
+      owner = described_class.new
+      @n1   = described_class.new
+      @set  = Oga::XML::NodeSet.new([@n1], owner)
+    end
+
+    example 'return a node from the node set' do
+      @n1.remove
+
+      @set.empty?.should == true
+    end
+
+    example 'remove the reference to the set' do
+      @n1.remove
+
+      @n1.node_set.nil?.should == true
+    end
+  end
 end