Created mock Ti.XML

This matches the portion of the Ti.XML API that is used by
titanium-backbone.
Allow XML syntax when creating views.

This supports attributes, nesting, and text nodes as outlined in #16.

One breaking change: the creation of namespaced views has changed from
iPhone::NavigationGroup to iPhone:NavigationGroup to match the xml
namespacing style, which uses a single colon instead of a double colon.
Change attributes._viewName to 'View' when viewName is 'div'
Added jade support

Jade produces XML, so all we have to do is generate that XML and then
use the new XML element builder to turn that XML into a Titanium view
structure.

Snazzy!

Closes #16.
Updated documentation for
Merge pull request #17 from trabian/xml_node_creation

XML-based node creation