Make Cancel button in Extra Camera Settings window work.

Hi Prof. Dempster:

My first attempt at pushing a patch to the forked repository.  In general things seem to be working, but I am troubled that when I "view branches" on my repo page it seems to show cancelbutton as a "base" branch rather than a descendant of my master branch.  If I have made an error somewhere please let me know, I believe I am getting the hang of using git locally but am new to the github website.

Thanks very much,
Darrin