[MPRIS] Docbook format

[Alex Merry]

Our current documentation-generating tools are based on those of 
telepathy.  They only allow html output (because the source document 
contains odd bits of html) and the tooling makes use of a non-standard 
Python module, Cheetah Templates.

I've added a "docbook" branch to the repo.  It generates docbook, and 
from that html, using only xsl.  The code is mostly stolen from 
secret-service, with several fixes and improvements.

It's not as pretty as the telepathy output was, but it does the job, and 
a bit of fiddling with stylesheets and xsl could go a long way.

The spec can no longer be used "raw" for introspection, but "make" will 
generate an introspection file full of EggDBus annotations generated 
from the telepathy introspection extensions (I intend to add QtDBus 
annotations as well at some point).

The impetus for this was that we don't fit into the system that is used 
to auto-generate the xdg specification web pages from the git repos. 
This new tooling should allow that.

Thoughts?

Alex


PS: sorry if any of you get this twice: sent it to the wrong list the 
first time.