Change autoresizingMask to only scale width and height.

This fixes an issue I'm having in a viewcontroller that contains 2
`UITableView`s.

These `UITableView`s are added to the main view, and sized using
AutoLayout.

In my `viewWillAppear`, I load some data over the network which can be
cached in a `NSURLCache`.

When this data is loaded from the `NSURLCache`, it will reload the
`UITableView`s _before_ `viewDidAppear`.

At this point, AutoLayout has not resized my `UITableView`s yet, and
they have a size of `CGRectZero`. If the `DZNEmptyDataSetView` is added
to the `UITableView` at this point, its `resizingMask` will cause it to
have a height that's exactly equal to 1/3rd of the `UITableView`'s
height.

This _looks_ okay, because `DZNEmptyDataSetView` doesn't `clipToBounds`,
but when you try to tap the `UIButton`, it will be rendered outside the
`DZNEmptyDataSetView` and thus not respond to touches.

This pullrequest changes the `DZNEmptyDataSetView` to _not_ have
flexible top and bottom margins, which fixes this issue for me.
Recalculate constraints every time.
Adds landscape orientation support to the Application sample project
Merge branch 'bartvandendriessche-play_nice_with_autolayout'
Merge branch 'everytime' of https://github.com/paystik/DZNEmptyDataSet into paystik-everytime
Makes sure all constraints are cleaned up, before updating
Refactors view constraints configuration, being sure unused views aren't still displayed.
Merge branch 'paystik-everytime'
Update README.md