To produce HTML versions of the "Tubes over XMPP" and "MUC Bytestreams"
proto-XEPs, you'll need to obtain xep.xsl from
svn://svn.xmpp.org:7398/xmpp/trunk/extensions/ and put it in this directory.
It's not distributed with Salut due to unclear licensing. As a result,
the proto-XEPs aren't compiled to HTML by a normal build - you have to run
"make -C docs proto-xep-html" explicitly.
