Gaze switch node

Using the A button on the joy pad to switch between a topic for gazing (dfault looking at people) and the remote control (means just cancelling the current gaze goal)
Merge branch 'hydro-devel' of https://github.com/cdondrup/strands_hri into hydro-devel
Merge pull request #49 from cdondrup/hydro-devel

Gaze switch node