Added orocos toolchain 2.8 repositories to indigo

This pull request adds some repositories that belong to the [Orocos Toolchain](http://www.orocos.org) and related ROS integration to the indigo distribution file in preparation for the upcoming 2.8 release.
One 3rd-party dependency, metaruby, was added compared to the hydro release.
Actually I don't know. I think our version has some patches to enable logging in real-time context. @psoetens?