Front end - get initial crude user interface working

[stevedahlberg]

Front end - get initial crude user interface working - maybe by picking just the Building and Businesses (Existences) aspects of it (leave Blocks for later) and have the user pick from a drop down list of either and specify a date (much like the "HistorySlider" control would later provide) and then be able to see an associated facade picture.

One that works, then get the ability read a mobile device's lat/long at the least to query for the nearest location and retrieve current content for that location .