[#848] Add a minimum acceptable width to the comment content

So that if it's narrower than a certain size, even the first few lines
drop below the icon instead of being squeezed by it.

This technique, however, ensures that the icon can still float beside
the comment text when the comment is wide enough that the words will
still be readable
Merge pull request #873 from afuna/min-width-comment-content-bug-848

[#848] Add a minimum acceptable width to the comment content