When confirming the visibility of unknown objects, don't wait to resolve the elements.

The superclass' implementation looks like:

    [self waitUntilTappable:NO
          thenPerformActionWithUIARepresentation:^(NSString *UIARepresentation) {
        isVisible = [[[SLTerminal sharedTerminal] evalWithFormat:@"%@.isVisible()", UIARepresentation] boolValue];
    } timeout:0.0];

"Unknown objects" == objects of unknown classes like the accessibility elements
vended by `UIWebBrowserView`.

We shouldn't wait to resolve the element because `-isVisible` is supposed
to evaluate the current state.
Temporarily use UIAutomation to check visibility in non-portrait orientations. (refs #135)

As a workaround for the failure of our visibility routine.
Ensure that `-[SLDevice setOrientation:]` waits for the device to rotate.

The previous delay was not long enough for the animation to complete on the iPad.
Reset the device orientation after deactivation on iPads running iOS 5.1 or 7.1. (refs #180)

On iPads running iOS 5.1 or 7.1, `UIDevice` forgets its orientation after deactivation.
This is not only unexpected but can mess with `-[SLElement isVisible]`
which (as of #180) falls back upon `UIAutomation`'s visibility routine
if (but only if) the device is in a non-portrait orientation.
Merge pull request #180 from inkling/jeff/135_landscape_visibility

Workaround the non-portrait-orientation bug in our visibility routine.