Allow players to roll dices and see stats block

[Javrd]

This is a request of two new features, in case you want to split the tickets:

1. It would be nice to have an option to allow players rolling dices and getting the log of the result in the combat log.
2. It would be nice to have an option to hide/show stats block (right-column) for each combatant (default hide for creatures/npc's and display for player characters) to players

We use improved-initiative to track combats in our online sessions, having this two features would avoid switching all the time between tabs to see player characters and roll dices during the combat.