[info] echo area should be quiet when moving to next node

[Benno Schulenberg]

When using the <[> and <]> keys, 'info' prints one of the following 
messages in the echo area at the bottom:

  Selecting Next node...
  Selecting first menu item...
  Moving Up 1 time(s), then Next.

  Moving Prev in this window.
  Moving Up in this window.
  Moving to `Prev's last menu item.

These messages are superfluous and distracting, in my opinion.  The 
echo area should only show something when an error is reported or 
when input is expected.

If however those messages cannot be removed, then please at least 
change them to all use the same style and words.  And make them all 
use the past tense -- in the age of 4 MHz processors moving to 
another node may have taken a few moments, but nowadays any
movement is near instantaneous.

Benno