First sentence in comments should end in a period
Delete a large number of unused imports

Many of these were imported purely to make using @link tags easier.  Not fixed
in this commit, but probably in a future one, is that the reason *that* in turn
happened is because there are a *ton* of @links to things like java.net.URL
when the paramters used and returned are not, in fact, java.net.URL, but rather
Strings that contain URLs.  I ended up not fixing that on this pass, instead
giving the full package name so the bogus imports could be removed.