Created general ROS msg package for Sample Return.

Messages and services that do not fit in a specific package
should be put here.
Added ROS msg dependencies to our msg packages.
Changed maintainer to Russel.
Adjust steering offsets
Skeleton saliency_detector package

This is non-functional
Moved image input out of class constructor
Helps to have a package.xml
This now runs, need to fix output
Fixed linking order error
Need to clear feature maps after each image
Folded node into single class to ease callback-driven publishing
Fixed dynamic reconfigure calls
Fixed parameter ranges, added horizon trim and threshold
Added simple blob detector, this crashes when filtering by color
Color naming class