Review included headers, tweak CMake code

[PeterBowman]

As a follow up to #56, C++ code should be thoroughly inspected with roboticslab-uc3m/developer-manual#19 in mind. Once all implicit and explicit dependencies are tracked down, CMake code should reflect proper include/link paths and linked libraries (OpenRAVE, YARP, Boost). This also spreads over find_package() calls, i.e. required Boost components.

This is a rather tedious and low priority task.

[PeterBowman]

Idea: cut down the number of search directories for headers (example) by taking advantage of YarpOpenraveBase's transitively included dirs.

Edit: perhaps OpenRAVE compile flags, too?

[PeterBowman]

See recent comments at #62 regarding the YarpOpenraveBase object library.

[PeterBowman]

This also spreads over find_package() calls, i.e. required Boost components.

TODO: set version number in find_package() calls for Boost and OpenRAVE (does OR impose its own Boost version, and is it accessible via CMake config variable?), update install docs.

[PeterBowman]

Idea: cut down the number of search directories for headers (example) by taking advantage of YarpOpenraveBase's transitively included dirs.

Edit: perhaps OpenRAVE compile flags, too?

Not doing for now, see #62 (comment).

[PeterBowman]

Done at ebca8bd.