Add ability to view weather stations on the map

[nwagenbrenner]

We should be able to view the weather stations as a layer on the map. Ideally, a user could click on them and also view some data about the station, like the most recent reading or a graph of the last 24 hours, and metadata about the station.

[masonwillman]

Additionally, if the user specifies a buffer, we should draw that on the map as well. This could look similar to the transparent blue box that is drawn when a user specifies the area for a DEM download.