Added getSelect to WebDriverElement

This PR includes the following changes -
1. `getSelect()` is ported from  CandyBean 1.1.3 to CandyBean 2.0.
2. A system test is added for `getSelect()`
3. Some system tests (doubleClick, dragNDrop, getAttribute, pauseUntilVisibleTest, isDisplay) are fixed and passing.
This isn't going to do the same thing that getElement does.  As noted in the JavaDoc, the objective here is to return a *child* of the current element, i.e. we're searching within a limited context.  Notice how the analogous method  getElement in this class does it:

WebElement childWe = this.we.findElements(WebDriverElement.By(hook)).get(index);
return new WebDriverElement(hook, index, this.wd, childWe);

It finds the element that matches the provided hook *inside of* the current element, by basing it off of this.we (the WebElement represented by this WebDriverElement) and then passes that WebElement to the new WebDriverElement it is constructing.

If you skip that step, this method will not limit its output to children of the current element like it's supposed to.  The constructor you're calling will find a list of elements like this:

this.wd.findElements(WebDriverElement.By(hook));

Note the wd instead of we -- that constructor searches the entire WebDriver search context (i.e. the whole page), not just this element.

Please update this method to ensure that it will only return elements which are children of the current element.