Updates to orogen/master wrt ROS

I've pushed two fixes to the orogen master branch:

1. Support for Fuerte for locating .tlb files
2. remove/rewrite cmake logic depending on ROS_ROOT.

-> Instead of ROS_ROOT, IS_ROS_PACKAGE *must* now be defined before
an orogen/typegen generated package will build/behave in a ROS
compatible way. When using the 'orocreate-pkg' tool, this flag will
be automatically detected by the generated cmake files (depending on
ROS_ROOT and the current ROS_PACKAGE_PATH), but merely including
UseOrocos.cmake will do the same trick.
The typegen/orogen cmake files do not include this file (and don't
need to), so a 'by hand' typegen/orogen generated package will never
decide to build as a ROS package, unless you explicitly use
'-DIS_ROS_PACKAGE' during your cmake configuration. This is the only
corner case where we might break previously generated packages.

I guess this closes a long open issue of correctly integrating
typegen/orogen with ROS environments.