Short Description:

Tips must come in ascending order (1, 2, 3,...) to reach the goal

Full Description

== This app is a collaborative work of Cliche123 and Nolidoux ==

* How it works:
You set a value for your goal then members must tip in ascending order (1, then 2, etc) until they reach the goal.
The total of tokens needed to reach a goal is equal to: goal * (goal + 1 ) / 2
That means the total of tokens gets big VERY fast when you put a high goal.
Here are the total tokens needed for some goal values:
5 => 15
10 => 55
15 => 120
20 => 210
25 => 325
30 => 465
35 => 630
40 => 820
45 => 1035
50 => 1275
55 => 1540
60 => 1830
65 => 2145
70 => 2485
75 => 2850
80 => 3240
90 => 4095
95 => 4560
100 => 5050

WARNING:
Because CB doesn't provide a testing environment yet, this hasn't been tested enough to ensure perfect behaviour.
If you find any issue or have any improvement to suggest, post about it in the comments.
Thanks.

* ChangeLog:
X Removed highlight on last tipper (I find it annoying)
X Removed unused code, simplified some parts
X Clarified goal text
X goal_description limited to 190 characters since we add stuff behind (but does it really matter if it goes beyond 255?)
X Changed panel to use 3_rows_of_labels
X When goal is reached, display something

* In progress:
~ Message when tips are sent after goal was reached (less intrusive than a goal update)
~ Update bottom panel when goal is reached
~ Display message when tip is too low to count (and explain why)
~ Don't update last_tip_username when tip was not counted
~ Send a chat notice to the performer after the app starts telling the total token needed for the chosen goal
~ Write total tokens needed to reach the goal in the bottom panel (optional)

* To do:
- Chat notice telling what numbers have been covered by the tip (optional) [e.g. next tip needed = 1, you tip 8, you get a message saying "Your tip covered numbers from 1 to 3" (and you wasted some)]
- Option for descending tips
- Choice for highlighting or not of the last tipper or biggest tipper
- Allow the model to start at a higher value than 1 (in case previous goal was interrupted)
- Allow to accept (or not) tips below the next tip needed
- Reject tip that are too low? Force tip values? (this needs an API update)
- Show the tip total in the settings box when the goal is set (not possible with the current API)
- Test it