Steam online leaderboards added!

Some notes about the Steam leaderboards feature:
There is a Steam leaderboard for each game flavor (except 'Practice Formula').
Only one score (the highest) per SteamID per leaderboard.
Your best score for each game flavor will automatically be submitted when the game starts up. (This means your existing high scores should be submitted as soon as you start the game with version 1.70 or newer).
New scores are automatically submitted at the end of each game.
Steam leaderboards can viewed by selecting 'High Scores' from the Options menu then selecting 'Next' on the local leaderboard viewer.
Only the top 100 leaderboard entries are displayed.
Steam names with non-Latin characters in them may not display correctly on leaderboards.
Steam leaderboards are auto-refreshed every 5 minutes when viewing them.
Steam leaderboards can be manually refreshed by pressing F7 while viewing them.

Additional changes:
Added an announcement (text and audio queue) when a new game flavor is unlocked.
Joystick deadzone option added to the 'Controls' menu.
Default joysick deadzone slightly increased.
'j' key also mapped to 'Action' button.
'Start' button on X360 pad also mapped to 'Pause'.
Fixed bug with friend placement in 'Rescue Relish' flavor.

Thanks to Ahoron for reporting the rescue friend placement bug and for the prompting to add flavor unlock notifications!
Thanks to PrettzL for suggesting the Joystick deadzone changes!
Thanks to ProPooperator for suggesting adding the 'j' key as an option for 'Action'!