* simple.el (delete-trailing-whitespace): New interactive function.

* simple.el (delete-trailing-whitespace): New interactive function.
* progmodes/ada-mode.el (ada-mode): Use it instead of
`ada-remove-trailing-spaces'
(ada-remove-trailing-spaces): Removed.
* textmodes/two-column.el (2C-merge): Recommend it in the doc.
* textmodes/picture.el (picture-mode-exit): Call it instead of
`picture-clean'.
(picture-clean): Removed.