Fix swipe action with target element: #3647

@Jonahss @imurchie (this reviewers of the first merge request that I closed because the new changes are a lot different) 

*  The original scope of this change was adding the ability to specify a destination element when doing a swipe.  Those are the changes you'll see in the server JS.
*  I added a bunch of tests.
*  When I started expanding the test suite for Android, I uncovered some nasty bugs w relative coordinates.  At least one was caused by copy/pasting.  I then discovered similar code (not nec buggy, but using the same patterns) in multiple places in the project.  I consolidated the logic to decrease the likelihood of bugs and ensure that absolute coordinates were all derived in the same way.
*  There's a bunch of spaghetti code.  If you have any suggestions on how I can get rid of it, lmk.
*  There's a change to the sample code that goes along with this.
*  I ran all the Android `touch` tests and they passed, with the exception of 'should work like `longPress` when released after a pause', which also failed for me before the refactoring


See my comment about execution time.

On 10/31/14, Jonah <notifications@github.com> wrote:
>>    if (env.FAST_TESTS) {
>>      beforeEach(function () {
>>        return reset(driver);
>>      });
>>    }
>>
>> -  describe('swipe', function () {
>> -    it('should be possible with press/moveTo/release', function (done) {
>> -      driver.elementByName("Content")
>> +  var _assertResultAndReset = function () {
>> +    if (!viewsEl) {
>
> Can this be easily turned into a function which accepts "viewsEl" as an
> argument? Rather than relying on a global var
>
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