Add logging for addresses in the area, but no matching street.
Make some more variables const and references.
Replace one instance of 111000 with DEGREES_TO_METERS.
Change minimum distance from one address to another to 3 meters.

This helps addresses located in (what seems to be) apartments be
included in OSM. As it is, this check doesn't seem too useful/important.
For some reason, having address2 be a const reference to the existing
data causes an error.
Split the data classes into a public class that contains setters and
getters and a private class that stores the data, and use QSharedData
and QExplicitlySharedData to manage pointer count.
Revert part of commit fa97c954, where multiple addresses within 0.5
meters of each other caused the building to be skipped.

The problem with this is that addresses that may be far away may cause
the building to be skipped.
Re-include addr:city based on discussion with OSM.
Move the code that does the actual conversion to a separate class
FultonCountyConverter. This allows a purely-console application to be
created.
Add option to automatically convert and quit.
Correct nearby address merging algorithm so that correctly merged
addresses aren't removed when updating the address for another building.
Bump up minimum area for buildings to 10 m^2.