Implement new_collection menu and add edit_collection menu
Implement new_collection menu and add edit_collection menu

Mod: Make do_new_collection functional.
Add: edit_collection() and do_edit_collection().
Add: Cancel button to selection_menu with optional callback argument.
Mod: Rename main() to main_menu() to prevent conflicts with the 'main' variable.

cferwin/Command-Line-Repetition