Migrating to consistent package naming

This is less significant now that KDL builds under catkin, but this is a PR which makes the following package renamings while maintaining backwards-compatibility:

`orocos_kdl` --> `kdl`
`python_orocos_kdl` --> `pykdl`

It also adds a metapackage called `orocos_kinematics_dynamics`

This PR replaces https://github.com/orocos/orocos_kinematics_dynamics/pull/1