We now prevent these variations:
* <hr/>
* <hr />
* <br/>
* <br />
We could enforce similar consistency for other void
tags, if we wished, but these two are particularly
prevalent.
The todo_widget was using the using a counter to store the key value of
every task. This would cause assiging multiple tasks the same key value
in a race condition. To avoid this we make "sender_id" a part of the key
along with the counter.
Also the `key` now not being a integer value, we can't use it to find the
index of the task using it. Thus, a function is made that will find the
index of task whose key is sent by the user to strike.
Steve Howell
majordwarf
Anders Kaseorg