Create new 'web' module
This is a module containing common classes above the browser specific
classes (edge.py, chromium.py). The browser specific classes inherit from
these web module classes.
- Move splitUIAElementAttribs(attribsString) from edge module to web module
- Move common implementation of edge.EdgeNode and rename to web.UIAWeb(UIA),
edge.EdgeNode now inherits from web.UIAWeb.
- Move implementation of edge.EdgeList and rename to web.List(UIAWeb),
edge.EdgeList now inherits from web.List
- Move implementation of edge.EdgeHTMLTreeInterceptor and rename to
web.UIAWebTreeInterceptor, edge.EdgeHTMLTreeInterceptor now inherits from
web.UIAWebTreeInterceptor
