Use defcustoms for variables which are supposed to be customized

[minad]

This helps a lot if one wants to find out where the configuration knobs are. I use this convention:

• defcustom mypkg-var for variables which are supposed to be customized
• defvar mypkg-keymap for keymaps or other special but public variables
• defvar mypkg--internal for all internal stuff

There are also many functions and variables which are called lexic- instead of lexic--. It would be great if you define the public interface of your package cleanly. I think most of the functions are actually private.