Added better support for reading and writing entry documents. Improved attribute support to more closely match the specification. improved efficiency of the entry sort extension.

<li>This release represents a thread safe release. The feed and all sub elements are immutable and thread safe.</li><li>A decent size reduction in the size of the api. the FeedReader and FeedWriter have been removed from the api. All reading and writing operations can be achieved through the FeedDoc factory.</li><li>Decoupled the stax-utils dependency from the root atomsphere library.</li><li>added support for reading and writing with arbitrary XMLStreamWriter classes</li><li>fixed issue with handling xhtml content type.</li><li>Email with questions.</li>