Lots of small fixes and improvements

Support for new devices.

In this version we have fixed the layout in calibration screen on iPhone 5/5S/SE.

In-app purchase is enabled in this version.

This version brings:
- new user features: 1/3-octave analysis and reporting
- improved accuracy or measurement on iPhone XS and iPhone XS max.
- home screen shortcuts
- redesigned measurement screen
- explicit control over starting and pausing a measurement
- bugfixes and stability improvements.

The update bring the following new features:
- support for iPhone 7 and iPhone 8
- optimised UI layout for smaller screen sizes

We are back! :)

- NoiSee has now been completely redesigned and rewritten to run on iOS 11. It runns on iOS 10 or latter.
- Optimised for accurate readings on iPhones 6, 6s and 7.
- History length can now be set.
- Some other additional settings.