Bug 254940

I wish there were more customizability in the behavior of the code completion pop-up. 

For example, suppose in java I declare two variables: `int rectangleHeight;` and `int rectangleWidth;`

Now I want to write a new statement `int rectangleArea = rectangleHeight * rectangleWidth;`

So I type `int rectangleArea = rectan`, and the autocompletion box pops up and it shows two options. If I press tab, it executes the autocompletion for the currently selected entry, which is the first entry, since I haven't pressed any arrows keys. However, this is not the behavior I would want. In fact, this behavior seems counter-intuitive to me because it is not how bash behaves. I would like to be able to configure autocompletion so that you have the same options you have with bash. For example, the way I have bash configured now, the first tab would extend `rectan` to `rectangle` and leave the completion pop-up open. Then subsequent tab presses would cycle between `rectangleHeight`, rectangleWidth`, and `rectangle`.

So in summary, my feature request is to be able to customize the behavior of tab in autocompletion the same way you can customize it in bash.