Search results should be sortable

Malone search results should be sortable

Malone search results should be sortable. The interface for this should be clicking on a column header once to sort by that column in the most likely direction, and clicking the same column again to sort it in the opposite direction.

"Most likely direction" here means: for the "Report" column, oldest first; for the "Target" column, earliest first; for the "Status" column, New->Accepted->Pending Upload->Fixed->Rejected; for the "Severity" column, highest to lowest; and for the "Reporter" and "Assignee" columns, none first, then A->Z.

Sort order should be remembered in your Launchpad account, but also set using a cookie so you can get the same sorting for multiple searches without logging in. If the account setting and the current cookie setting disagree, the account setting should win and the cookie should be overwritten.

Sort orders should eventually be residual (e.g. clicking "Report" then "Status" then "Target" should produce a list sorting by bug ID within each status within each target), but doing that can be left for later development.