Add time since last detection to the fire layer

[changerate]

When fire coordinates are detected, the time of detection (down to the minute) will be logged in the DB.
The user has the ability to store see the time displayed on the map.

In the future, perhaps add summerizations to the times:

• 12 coordinates of fire
• instead of showing 12 times (which will probably be within a minute of eachother)
• average out the time when the spots of fire become to clumped