ScrollWidget: remove old debugging output
MentionsTimeline: Don't show everything twice

This was happening whenever the user opened the page for the very first
time via the keyboard shortcut.
TweetListEntry: Reset the retweet_button at the correct position

Which is on focus-out of the entire row, not the reply_entry.
TweetListEntry: Don't hide the quick reply stuff...

... on focus-out of the reply_entry. Funnily, focusing the reply_button
and pressing return just activated the row, not the button.