Added CWVector and PPI to inital data

- Added CWVector class that makes it easy to work with vectors in JS
- CWGestures now uses vectors

- Added CWiDevice class that contains information about the current iOS device. For now, these are mainly pixel density information
- Added PPI to the app state information
- Added PPI to the initial data
- CWPinchManager now uses the PPI sent by the devices. This is bugged right now, because the PPI for the master device are missing