Introduce custom debounce times for build configuration

[object88]

Some users may want the debounce functionality more or less sensitive. Some IDEs may not auto-save every time that a file looses focus, making the user to save all files at once. This would imply a very low debounce time. Others may save every time that a file looses focus, causing file change chatter. A high debounce may reduce the build tool load.

Debounce could be expressed in milliseconds.

Possible configuration file format:

"build": {
  "debounce": 1500
}