Fix #899: Keyboard: Restore _focusNode even if grid isn't focused
CHANGES.md: Note Keyboard _focusedNode preservation fix
Fix the top-heavy manual tree test
Fix #882: Fix gallery view in demo to use display: inline-block
Improve styles of multiview demo

Incorporates layout styles from the version on dgrid.io
Move documentation from the GH wiki into the repository

Based on @edhager's work of similar nature for 0.4
Docs: Mention `dgrid-autoheight` (added in 0.3.14) in migration docs
Update version for tag
Update version for dev towards next 0.3 release