I have created branch flume-1262 and have a working site build that fixes this problem,
FLUME-1256 and FLUME-1282. It isn't complete yet as most of the sub-projects need and index file created to describe them. Originally I was going to keep the Sphinx part of the build, but after seeing that it didn't integrate well into the project sites I chose to incorporate the documentation into the normal site build.
To build the project just run "mvn package" or "mvn install" as normal. To build the web site run "mvn site" and then "mvn site:deploy -DsiteUrlDeployment=file:///Users/xxxx/flume" where xxxx is your userid (on a unix system anyway). To view the site browse file ~/flume/index.html.
The build should also support using "mvn release:prepare" and "mvn release:perform" to do a release.