Patch: Build DTD docs, provide -doc subpackage in RPM

[https://www.google.com/accounts/o8/id?id=AItOawnSjgovXZr-_V3vGkvMSR0pc5LDykRc1Nc]

I've attached a patch that does two things:

1. Uses xs3p (​http://xml.fiforms.org/xs3p/), an XSLT stylesheet, to do transforms on the Bcfg2 DTD and automatically generates documentation on the DTD. I added a build_dtddoc command to setup.py that performs the transforms using lxml.etree and puts the resulting HTML in build/dtd. I also added some documentation to bundle.xsd; it's not much, but should demonstrate the ease with which the DTD can be documented with this system in use.

2. I added both build_sphinx and build_dtddoc commands to the RPM specfile, and added a -doc subpackage to put the resulting HTML in. The specfile builds successfully on CentOS 5 and Fedora 13.

There are a couple of known issues:

1. The output from xs3p uses pop-ups to present documentation on non-global components, which, due to the way the Bcfg2 DTD is written, is most of them. This is ugly. It could be improved by modifying the XSLT, but I'm not a web designer and wasn't sure the best way to present that information. Either way, this is a start.

2. The python-sphinx10 package in EPEL 5 apparently has a bug where it fails to add itself to sys.path after installing. There's some ugliness in the spec file to get around that.

[https://www.google.com/accounts/o8/id?id=AItOawnSjgovXZr-_V3vGkvMSR0pc5LDykRc1Nc]

Patch for misc/bcfg2.spec

[solj]

Added in a193b1edeebc0f96cc15e9702af97a0480cd9c4b. Thanks for the patch.