Reviewed statsandaccounting.md

@vecna this specific is ok.
I've changed minor things (rewriting them in a more formal way but the concept is complete and exaustive. 
I've changed some internal detail that talked  about Pickle to JSON do not bother to this is really a minimal change we can apply when finished)
The only part that need to be completed as it is not so much clear is the last part "AnomalyLogging". can you please work a little on this?