Add license file
Merge pull request #37 from tomhughes/license

Add license file
element() accepts JS objects
Divided different elements into separate files.
Removed unused value property from XMLElement
Cleam up requires
XMLBuilder.create accepts JS object to fully build the document
JS conversion for attributes, cdata, text nodes and comments'
Removed children array from XMLBuilder
Options are merged at create()
Convert raw nodes in JS objects
JS object conversion accepts functions returning objects and arrays
insertBefore and insertAfter delegate to element
Moved name check to XMLElement
JS conversion covers all generic cases. Closes #35
Added aliases for node()
Added tests for node()
Renamed attkey decorator
Ignore empty decorators when converting JS objects
Eval functions if passed directly to element()