Implement xml and innerXml
Implement empty and remove
add append and prepend
Implement addNextSibling and addPreviousSibling
Add append and prepend (shorthands)
add before and after (Shorthand)
extract manipulation methods to protocol
Extract query protocol
revise node creation
Remove the useless encoding params
Add traversal and test cases
Add set attributes
add method to remove the namespaces
add podspec