Patch to allow opencv_contrib modules

[jpswensen]

For my Mechatronics course, I wanted to add the opencv_contrib modules because we use the opencv_contrib aruco module for tracking robots for a midterm project. This script is awesome and saved me loads of time. Attached is the results of "git diff" to add this as an option through a YES/NO variable at the top of the file (like is already done for opencv_extras).

If you want me to fork and make this into a pull request, I can, but thought a patch might be easier for others to find/apply than navigate a fork and leaves your repository as the authoritative source.

add_opencv_contrib_option_diff.txt

[jetsonhacks]

Excellent! Thank you kindly.