Try to fetch all unread lines if that is a reasonable amount

Partially fixes #139 in that it tries to accomplish this, but until we can request
only non-filtered lines from WeeChat, the best thing we can do is guessing.
Merge pull request #224 from lorenzhs/fetchall

Try to fetch all unread lines if that is a reasonable amount
Bigger logo on landing page

I rendered the svg with inkscape
Merge pull request #227 from lorenzhs/titlepage

Bigger logo on landing page