(edit_load_position): New function, load position.
(edit_save_position): New function, save position.
(edit_init): Take new argument "line". If it's 0, load position
from .mc/filepos.
(edit_clean): Save file position to .mc/filepos even if the file
is not being saved.
* editwidget.c (edit): Don't set the initial line, pass it to
edit_init().