* Holds all the settings for the app
* Allows core plugin to override default values

Also added ui support for multiple complex item types

Done by using GridLayout

Allow plugin to define default font size, toolbar height and option to display/hide plan view selector.

- Shot Interval in Survey
- Much change to time/distance calc

This makes text show up better on map images

Shows horizontal/vertical scroll indicators

Sony a6000 ILCE-6000 with 16mm lens.
Source : 
http://www.sony.co.uk/electronics/interchangeable-lens-cameras/ilce-6000-body-kit#product_details_default

it's not a typical APS-C sensor, proper size gives more accurate
calculations.

The 22mm as stated on the lens is actual, not 35mm equvalent as on smaller
cameras.  - So it was wrong to reverse calculate for crop factor.