Update envelopeSelector.js

Added the `zoomExtent` option.
When getting the envelopeEntryDialog object via data, now using "uiEnvelopeEntryDialog" instead of "envelopeEntryDialog"
Update envelopeSelector.markdown

Added `zoomExtent` option documentation.
Added "mapLoad" event to envelopeSelector.js.
Envelope selector now inherits from arcGisMap.
Fixed call to parent "callMapFunction" function.
Update addressFinder.js

Check for type of element (to ensure HTMLInput) modified to work with IE8.
Merge pull request #2 from WSDOT-GIS/master

Merged changes from master