It causes problems because it includes px4_nodehandle.h which in turn
includes <functional>, and this is not available on NuttX

Restructuring of generic middleware support files, wrapping of the main ROS calls, skeletons for publishers / subscribers

Move NuttX configurations out of the NuttX tree proper. This reduces the diffs we have to carry against the NuttX upstream repo to just our local patches to the NuttX code itself.