[JointTrajectoryController] Enable position, velocity and acceleration interfaces

[destogl]

this addresses #135 and it should replace #36.

Currently the only version with commented-out code to work with KUKA robots.

Proposal: we should choose between different versions using parameters.

[bmagyar]

We could have a similar approach to forward_command_controller, with joint_trajectory_controller having a parameter to pick the "flavour" and some derivatives that hard-code this parameter.

[destogl]

We could have a similar approach to forward_command_controller, with joint_trajectory_controller having a parameter to pick the "flavour" and some derivatives that hard-code this parameter.

To keep this PR shorter I will add those into a separate one.

Before merging we need to:

• add test for not allowed interface combinations
• add test for velocity and acceleration
• check what is happening when having all three state and command interfaces and why are those braking tests

[AndyZe]

Reviewed a couple hundred lines... I'll come back for more later

[destogl]

Addresses: #4, #49, #118

[destogl]

OK, now I only have one two more test issues left:

1. uncrustify and cpplint and fighting over braces
2. the new test throws some exception and I cannot find from where
3. Update documentation to proper files.

Please help.

[bmagyar]

the actual controller implementation looks good but I think we should reorganize things a bit to make the core more maintainable

[jordan-palacios]

Overall LGTM!

[bmagyar]

I like what's being done here with the shared understanding that we need to refactor it.
There are several places in JTC already that are not ideal for realtime-safety already, those should be ironed out in one go probably.