Expand metrics beyond Accuracy and WPM

[chikamichi]

Expand metrics/records — some of those requiring updated-while-typing computations:

• Longest perfect accuracy series
• Words (actual words) hit/total (ie. words nailed on first try)
• Total time
• Mean time-to-press (how much time before the user typed the next character)
• Most frequent inacurate characters
• % faster/slower than beat