add ability to open status by URL from search (fix #53)

loaded status; do not preload submitted statuses into community/public
timelines, unless those timelines have already been loaded; do not
close streaming API connections for community/public timelines, once
they have been established (most users navigate back to them eventually)

from zooming in on them

to only those from local users; Add link to "extended information" to
getting started in the UI; Add defaults for posting privacy; Change
how publish button looks depending on posting privacy chosen

Changing the way the background image is positioned and the box is sized should fix problems with the text overlapping the image on mobile browsers and Edge.

nested inside a common parent (<Account>), instead they all embed <HeaderContainer />

for extremely wide monitors

improved how "show more" link looks

Currently, the getting started text fails WCAG standards for color contrast by a lot. Especially on the part overlapping with the elephant graphic which is nearly unreadable even for users with 20|20 vision. This change doesn't fix the elephant overlap but at least makes the text meet AAA WCAG Small Text color contrast standards, making it easier to read.

affected, replaced onClick handler with onMouseUp/Down to detect text
selection not trigger onClick handler then

application website validation, don't link to app website if website isn't set,
also comment out animated boost icon from #464 until it's consistent with non-animated version

This allows other platforms such as Windows, macOS and iOS to use their system fonts rather than downloading a copy of Roboto. It also makes the app feel a little closer to native on those platforms!