Parts of this require C++11

[chhtz]

No description provided.

[saarnold]

I guess C++11 code was introduced with the use of the explicit specifier in the PoseWithCovariance constructor.
This PR should be applied on the main repository: https://github.com/rock-core/base-types
Where we can decide to either merge it or remove the explicit specifiers.

[chhtz]

This may actually be caused by a local hack by me. I'm currently essentially including a (or referring to) a local Rock workspace. Therefore, Vizkit3d is found, which apparently requires C++11, e.g., there is a std::shared_ptr<ClickHandler> in Vizkit3DPlugin.hpp.

I'll try again with a "rock-free" ROS build.