Upgrade to Selenium 2.31.0

v2.30.0
=======

WebDriver:
  * Fixing a bug introduced by a change in how we get already logged
    messages from the console service in firefox. This allows us to
    function with firefox 19
  * FIXED: 1181: Improved loopback detection
  * FIXED: 1627: Implementing ability to use auto proxy in
    HtmlUnitDriver.
  * FIXED: 3652: moveToElement with offset should consider 0 as a
    valid value, not as "undefined".
  * FIXED: 3868: Better ephemeral port range selection.
  * FIXED: 4107: Added prebuilt version of the SafariDriver extension
    to the client jar.
  * FIXED: 4821: WebDriverBackedSelenium works when added to project
    via maven.
  * FIXED: 4940, 5075: Added iceweasel to list of firefox variants.
  * FIXED: 5022: Text node with overflow:hidden and height/width 0 to
    not be visible since we cant see them.
  * FIXED: 5030: Only send files to upload, not directories.
  * FIXED: 5079: FluentWait.until(Predicate) method does not propagate
    predicate message.
  * FIXED: 5109: We should show elements visible if there is a pixel
    visible.
  * Semi-private change: Changes in the Coordinate class.

JS:
  * Update WebDriverJS to support parallel flows.  This change renames
   several low-level classes and functions in the promise module:
    
      promise.Application                                 -> promise.ControlFlow
        #schedule(string, function)                       ->   #execute(function, [string])
        #scheduleTimeout(string, number)                  ->   #timeout(number, [string])
        #scheduleWait(string, function, number, [string]) ->   #wait(function, number, [string])
   
    The old schedule* functions are still present, but will print a
    warning message if called. They will be removed in 2.31.

RC:
  * Added ability to use relative path to an -htmlSuite file.
  * FIXED: 5113: Implementing GET requests support for RC protocol.