Add Option for Repeat Key Presses

[lanijw]

At the moment when I press a key multiple times it only show up in the list once. Since I often use vim to edit code during presentations multiple key presses often have a different meaning than just pressing the key once (yy, dd, etc.). Ideas for the implementation details:

• Display a small number as a tag in the corner of the key for amount it was pressed
• Let the user select how many times the key should be shown if it's pressed repeatedly
• Simply display the key as many times if the user enables that option.