Trivial doc/whitespace fix.
Fix ResourceManager exception messages.

- Print derived class name instead of the less descriptive and more cryptic
  base class name. Eg.

  "hardware_interface::JointCommandInterface"
  instead of
  "hardware_interface::ResourceManager<hardware_interface::JointStateHandle>"
Merge branch 'hardware_interface_rework'
Restore documentation of handle parameters.

Documentation that was previously in the interface classes before the
hardware interface rework has been moved to the handle classes.