Width of Alert

[manide]

PKAlertController seems to use the minimum of width/height of the screen and substract alertOffset from this to calculate the width of the alert.
On contrast, system alerts seem to use always 270 pixels as width for an alert.
PKAlertController should either replicate the system's behaviour and/or offer an API to configure the width of the alert (alertOffset is not in the header).

[roothybrid7]

That's hardly necessary for me.
Patches, Proposal of implementation and so on are welcome.