added dynamic parcel display;added about modal + wim ident

[BlakeDraper]

• implemented a dynamic layer for parcels for display purposes. the feature layer display was causing the printing to fail when more than a handful of parcels were within the extent because the webmap_as_JSON property was huge, presumably due to the client-side graphics. dynamic layers work better with the amount of features for printing purposes. The featurelayer remains in there for selection purposes.
• added the tabbed "About" modal and the "Powered by WiM" identifier to the sidebar.