Decoding of zero padded XML entities

This would previously fail due to the lack of an explicit base to use
for Integer().

lib/oga/xml/entities.rb

@@ -72,7 +72,7 @@ module Oga
 
         if input.include?(AMPERSAND)
           input = input.gsub(CODEPOINT_ENTITY) do |match|
-            [$1 ? Integer($2, 16) : Integer($2)].pack('U')
+            [$1 ? Integer($2, 16) : Integer($2, 10)].pack('U*')
           end
         end
 

spec/oga/xml/entities_spec.rb

@@ -69,6 +69,10 @@ describe Oga::XML::Entities do
     it 'decodes &#x3C; into <' do
       described_class.decode('&#x3C;').should == '<'
     end
+
+    it 'decodes numeric entities starting with a 0' do
+      described_class.decode('&#038;').should == '&'
+    end
   end
 
   describe 'encode' do