* Structure - class added to create objects dynamically

* xover.subscribers - added to manage dynamic attributes
* xover.subscribeReferencers - refactored and replaces xover.evaluateReferences
* xover.listener.on(['pageshow', 'popstate'] - added initialization for seed
* xover.session.getter - uses history.state.context to keep record of referenced site variables
* xover.session.setter - xover.evaluateReferences replaced by subscriber evaluation
* xover.site.getter - uses history.state.context to keep record of referenced site variables
* xover.site.setter - refactored to fix bugs and trigger subscribers
* xover.site.state.getter - refactored to use subscribers
* xover.site.state.setter - refactored to use subscribers
* xover.site.seed.getter - simplified
* xover.site.seed.setter - bug fixed
* xover.site.active - simplified
* document.addEventListener("DOMContentLoaded") - fixed xover.subscribeReferencers call
* xover.xml.combine - target.staticAttributes added to fix attributes
* xover.dom.combine - bugs fixed and prevents non appended scripts from running
* xover.dom.beforeunload - removed replaceState
* scope_handler - bug fixed
* XMLDocument.prototype.render - xover.subscribeReferencers replaces xover.evaluateReferences' call