Backend feature requests

[rhaamo]

What needs to be implemented, or fixed:

• Log every spot in archives
• Statistics of archives (day, month, year)
• Coverage plot of the receiver (AIS, ADSB), per source
• Non-map template
• Error page
• AIS: Send IDs+text instead of only text; Front can uses both for ease.

[rhaamo]

• https://github.com/electricshaman/squitter ADSB but RAW instead of SBS
• https://github.com/clupprich/ais AIS
• https://github.com/pentlandedge/aisle AIS