[Webtest] [dev] Locators

[Marc Guillemot]

Hi Mittie,

I've seen your commit "show need for locators" preparing for re-introduction of locators. I (now ;-)) agree with the 
need of the <index> locator for a button but I propose an other solution instead of the form locator. The old form 
locator only allowed to locate a form when clicking on a button. This was fully ok as there was no need to have the form 
"located" before as the set inputs were buffered. This isn't the case anymore because actions are performed directly on 
the form. This introduce the need for a "locateform" (or "selectcurrentform") step that can be used before a <setXXXX> 
or before a <clickbutton> making the nested form locator useless. Is this ok for you?

Marc.