Merged from trunk 5366:5372

Merged from trunk 5366:5372

For bug #158931, add some release notes to explain performance penalties for
dependency calculations.

For forward compatibility, make metadata_overlay pass any additional positional
and keyword parameters into the super constructor.

Manpage fix for bug # 158983, thanks to Fabio Correa for the patch (WarnerBro)

More code cleanup, packagetree appears to be completely unused, so lets remove
it in favor of inheriting from object (WarnerBro)

Docstrings for doebuild (WarnerBro)

cptot appears to be unused, punting it along with this commented out function,
it appears to be unused as well. (WarnerBro)

svn path=/main/branches/prefix/; revision=5375