opencv3.x update

[arrenglover]

the project needs to be updated to work with newer versions of opencv.

• [x] update the library to compile with opencv3
• [x] update the cli to compile with opencv3
• [x] find compiler definition for if opencv_contrib is installed with xfeatres2d (i.e. for non-free features)
• [x] update all new feature detectors and extractors available in opencv3
• [x] update the settings file with values for the new detectors and extractors
• [x] update readme