Bugzilla spring cleaning

Hi.

There's a few cleanups I've wanted to see happen on our Bugzilla site.

The ones that are currently on my mind are these:

1) Remove old entries from the "Versions" list.

Do we really need 3.x and 4.x here?
Personally, I can see deleting 5.x too, and replacing all of them with
a "catch-all" field for old releases.
[I can also see deleting 6.x, but "baby steps" ...]

I can imagine their appearance in some old bug making it
hard/impossible to accomplish this, but I won't know unless I ask.

1b) IWBN to reverse-sort the Versions list.

2) The "Target Milestone" list could also use some trimming.

Comments?