Rules for XP accumulation

[matt-dray]

XP is accumulated automatically over time. It should also be accumulated when a positive action happens to improve its status (played with, fed, or cleaned).

• How much XP should be gathered per action? It's completely arbitrary, obviously, but actions that collect XP should be relative to each other. XP for simply existing over time should be small; a battle win should reward lots of XP (Battle #8)
• Is there a concept of negative XP? Rather, I think the 'punishment' for inaction should be zero accumulation. Otherwise maybe there should be an HP system instead (health is lost if the pet is unhappy, hungry or dirty, but gained if these problems are fixed by the player)?

(Don't think about this too hard; no-one is actually going to play with this package.)

[matt-dray]

.update_blueprint() has a current default of xp_increment = 5L (i.e. 1 XP every 5 mins of 'life'), which keeps it ticking over and reduces the need for a user to attend to the pet all the time. I'm probably not going to test this passive accumulation very much.

[matt-dray]

Maybe apply a bonus XP for each day of life, rather than accumulated above periods of minutes.