Option to search when clicking on flair

fixes #1786.
Not sure if this is the best way to do it (do we want to be changing an element's type/tag?); I can change it to just `location.href = ...` if you prefer.
Results sorted by new because hot sorting on searches doesn't seem to be the same as hot on the frontpage (i.e. search for the flair of the top post in a subreddit, and it isn't even on the first page of search results when sorted by hot).
instead of replacing the `span.linkflairlabel`, how about `e.target.textContent = ''; e.target.appendChild(newElem);` instead?   i'm worried about subreddit CSS that selects on `span.linkflairlabel`