I tried to minimize the changes to configdialog.  There were more I wanted to make, like reorganizing the order of the functions, but I didn't want to make the diff too crazy.  I changed some variable names because all of them had 'keys' in it and I couldn't keep track of them.  It was almost as descriptive as single letter variables!  ;-)   I think I made the new names inline with what had been done on the font and general tabs.  Again, there were more renaming changes I wanted to make (such as key_set to keyset), but I didn't want every line to be a diff.

Also, I used the name 'keyset' to refer to the section names and the keybindings to refer to the option:value pairs.  Some old vars in configdialog weren't changed to reflect this 100%, but the comment should be correct.

I did not include deactivate_current_config and activate_config__changes since those are not really specific to keys.  There are also invoked from themes and from apply.

I have notes for some of the other coding changes I'd like to make once this is in its own class.