Reduced the frequency of refreshes, to avoid running over the Twitter call limit.
Post windows now use the same style as the main tweet window.
The length of posts is now calculated intelligently to account for link shortening. So if you paste in a long link, it won't use up all of your character count, as the link will be shortened in the actual post.
Auto-completion list for @users in post window now includes all users that the app has encountered.
Now correctly restores cached tweets and users when loading.
Added subtle gradient to window backgrounds.
Fixed beta Sparkle feed URL (the app was looking at the non-beta feed instead).
Updated the manual with screenshots of new posting UI.
Fixed window resizing.
Improved sorting, refreshing with new items.
Changed user guide code to be sandbox-friendly (copies guide into the Caches folder and opens it from there).