Add comment "digging" and "burying"

[David Siegel]

The hundredpapercuts project is getting a lot of attention, and drawing many new users to Launchpad from sites like Digg and reddit. These users are not familiar with how we work, or how reporting bugs works in general, and will often post unhelpful "me too" comments, or hurtful "you guys suck, fix this now or else I will switch to windows" comments.

To help those of us who are interested in getting work done, without all of the noise, I suggest allowing us to "dig" helpful comments, and "bury" unhelpful or outdated comments. This allows us to hide unhelpful comments, and it allows us to update old bugs by hiding outdated comments. This makes it easier to work with the bug, and makes the bug faster to load, as buried comments can be hidden and not loaded by default. Bug karma could also play a role in determining the result of digging/burying. For example:

John signs up for Launchpad to comment on a bug linked to from Slashdot. John comments "M$ suxx!" on the bug and clicks "dig comment" in an effort to promote it. He also has three of his friends sign up and dig his comment. A few minutes later, Jane, who has 8,000 bug karma, opens the bug and clicks "bury comment" on John's comment. Jane casts a much more authoritative vote than John and his friends, and it is collapsed by default when the bug is viewed from now on.

[Martin Albisetti (beuno)]

I think we should think very hard about this, as we will need it as Launchpad grows. We may likely want to take into account who is digging or burying the vote, as the project owner will likely have a better idea of a valid comment than a random person.