Follow state of bugs marked as duplicates

There are currently two types of relationships between error reports and Launchpad bugs. There are Launchpad bug reports that were created by someone from the ubuntu error tracker which contain details from the error tracker, and crash reports that were also sent to Launchpad (most likely because the user was running the development release). If the second type (crash also reported to LP) is marked as a duplicate I think it makes sense to link the master bug, however with the first kind (bug created in Launchpad) I don't think it does. I feel this way since it will be challenging to find which duplicate bug is the one reported from errors and because the one from errors should be information rich and likely shouldn't be a duplicate of another bug.

Another issue with was mentioned in the duplicate bug report:

"One issue with linking to the wrong bug report is that the most common problems table is showing that the bug is not fixed when in fact it is."

Bug reports from Launchpad are imported via the daisy script import_bugs.py and this happens on a daily basis. Given that the "LaunchpadBug" column is used in at least two separate places, I think it makes sense to look for duplicates during the import process or to fix the apport_duplicates database.

If we use the former then bug_is_fixed() in launchpad.py should give one an idea of how to get information about a bug.

An example of the change can be found here:

https://errors.ubuntu.com/problem/54eb003414e31e329037351ef35685138db774d7