Support full-screen captures

[cmathew]

Is your feature request related to a problem? Please describe.
To fully capture a scrollable screen, one must collect a series i.e. by scrolling and screenshotting each vertical "page"

Describe the solution you'd like
a way to render full content to one image. Recyclerviews probably prevent one big screenshot from being captured at once. Perhaps instead, ScreenCaptor could scroll, capture, and stitch multiple screenshots together automatically

Describe alternatives you've considered
Somehow simulate a very tall device at screenshot time so all content is rendered at once. Doesn't scale (if it's possible at all)