New app: Media sharing - broadly fixed the sharing screen, to use neater text and the colour scheme.
- you can select a result from the History screen, and see the share button appear...
- ... that that button, and you can share a screen grab of the test result.
- NB: we share as an image "in the standard Android manner", i.e. without an app specific
  screen listing e.g. Twitter/Facebook/email as specific items.