Arm Forward Kinematics

[IanTheEngineer]

This adds Kinematics functionality to the Sawyer Simulator:

• [x] Adds Forward Kinematics Service
• [x] Adds Endpoint States topic: /robot/limb/right/endpoint_state

[IanTheEngineer]

There are ways around it, but the creating a unique pointer from a raw pointer in a robust manner requires C++14:

std::make_unique<KDL::ChainIdSolver_RNE>(kin.chain, gravity);

As for auto, there's a large discussion in the C++ community about its usage. I have a book references that recommend it be used by default, unless you have a reason not to (Item 5 in Effective Modern C++, by Scott Meyers), but this stackexchange answer summarizes the rational nicely: https://softwareengineering.stackexchange.com/a/180616/112028

To be honest, since this is a library targeting Ubuntu 16.04 and later, which ships with gcc 5.04 and has full C++14 capabilities, I see no reason to avoid using the more recent version of the language.

[rethink-forrest]

I defer to following the Google style guide for when to use auto: https://google.github.io/styleguide/cppguide.html#auto

[IanTheEngineer]

I agree with you there:

When to 'auto':
(Allowed) When the type is clear from local context (in the same expression or within a few lines). Initialization of a pointer or smart pointer with calls to new commonly falls into this category, as does use of auto in a range-based loop over a container whose type is spelled out nearby.
(Allowed) When the type doesn't matter because it isn't being used for anything other than equality comparison.