Replaced the 'res' property in photo prompts with 'maxDimension'.

The 'res' property was not being used, so it has been deprecated. A new property, 'maxDimension', will take its place as it more explicitly defines what the property is meant to do.
Added the default observers.

Now, when a server is first created the default servers will also be created. The update script, however, will not add these observers because it is presumed that they, either, already exist or aren't desired. To add them, go to the db/settings/default_observers.sql file and execute the appropriate lines.

Closes #503