[boost] [fusion] Minor interface change

Hi Y'all, Heads up. There will be a minor interface change. vector0 will now be a template: vector0<> to better reflect MPL. This also addresses Boost Trac ticket #1608: https://svn.boost.org/trac/boost/ticket/1608 Please adjust your code accordingly, or holler if you have any complaints. Unless there are objections, I'll commit the code as soon as all the relevant regression tests pass. Regards, -- Joel de Guzman http://www.boostpro.com http://spirit.sf.net