Fix issue with fractional title/message sizes

Text being drawn with fractional sizes may not always render
properly—see the [NSString UIKit Additions Reference](https://developer.apple.com/library/ios/documentation/uikit/reference/NSString_UIKit_Additions/Reference/Reference.html#//apple_ref/doc/uid/TP40006893-CH3-SW37) for more info.

This commit just changes the working frames (for both the title and message) to a rounded equivalent.

Here's an example, before the change:
![Before the Change](http://i.imgur.com/3LqgFfi.png)
... and after:
![After the Change](http://i.imgur.com/EsxwSd5.png)