Fix an exception: 'obj is undefined' in edit_area().
Fix a number of dialogs that didn't save/restore the background text.

Now, I don't understand the input "loops" for Source Address and
Upload Name - hitting "Enter" doesn't exit the input loop, you have to hit
ESC. This behavior is inconsistent with every other Synchronet configuration
program/script behavior, but I'll leave it to the author(s) to address that
oddity.