Fix issue with bindData() not allowing empty fields
Allow merging of children nodes
Source is already typehinted
Fix test
Merge pull request #3 from wilsonge/patch-1

Allow merging of children nodes
Update RegistryTest.php
Merge pull request #2 from joomla-framework/mergeFix

Fix issue with bindData() not allowing empty fields
Merge pull request #4 from wilsonge/patch-2

Add unit test for setting null values in constructor
Add PHP 5.5 to Travis config