Do not use a separate column for the checker [#230]
Update the screenshot
Add a Wiki links
Update error list highlighting upon refresh
Add list-flycheck-errors alias

Fits in the list-* scheme of other Tabulated List Mode derivates
Turn error list messages into source buttons [#230]

Messages in the error list are buttons now, which when pushed, jump to
the source of the error.
Fix markup
Mention the error list in the README