Fire control clicks immediately and start looping after a short delay

[mdingena]

Context

When clicking a control button too quickly (as in, mouse isn't held down longer than 100 ms) the click doesn't register at all. A better user experience would be that any click, no matter how long pressed down, would register at least once.

Another good user experience is to start repeating clicks (due to holding down the control button) only after a brief delay. This is so that minute change can be made with single clicks without the risk of accidentally triggering the fast loops (100ms cycles).

Closes #27

Changes

• Added a call site for controlClick() outside of the setInterval() body. This will trigger a call immediately when clicking a control button.
• Wrapped the setInterval() loop in a setTimeout() to delay the loop by half a second (in line with other Windows user experiences, such as holding down a key on your keyboard).