kconfig/lxdialog: handle newline characters in print_autowrap()

When exiting menuconfig with unsaved changes, a dialog like
the following is shown:

        Do you wish to save your new configuration ? <ESC><ESC>
        to continue.

The author of the dialog text specified a newline after the '?',
and probably expected it to be processed, so let print_autowrap()
handle newlines propperly.

Also, reword that dialog's second phrase with a real sentence.

Signed-off-by: Dirk Gouders <dirk@gouders.net>
Tested-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Reviewed-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
[yann.morin.1998@free.fr: very slightly tweak the commit message]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>