Accumulate virus rewards gradually when hardware changes

[renatomassaro]

Just a brainstorm I was having earlier today:

If hardware changes, or anything that affects the virus reward upon collect:

• Save the amount the virus would rewarded if collected now

When collecting:

• Check if there are accumulated rewards saved on DB.
• If so, sum all of them and get the last accumulation date.
• Add to that the reward of (now() - last_accumulation_date)

[renatomassaro]

Actually this behaviour is quite similar to the one used on Process.Scheduler (with the last_checkpoint thing)