This is a terse description of the new features added to readline-5.1 since
the release of readline-5.0.

1.  New Features in Readline

a.  The key sequence sent by the keypad `delete' key is now automatically   
    bound to delete-char.

b.  A negative argument to menu-complete now cycles backward through the
    completion list.

c.  A new bindable readline variable:  bind-tty-special-chars.  If non-zero,
    readline will bind the terminal special characters to their readline
    equivalents when it's called (on by default).

d.  New bindable command: vi-rubout.  Saves deleted text for possible  
    reinsertion, as with any vi-mode `text modification' command; `X' is bound
    to this in vi command mode.

e.  If the rl_completion_query_items is set to a value < 0, readline never
    asks the user whether or not to view the possible completions.

f.  New application-callable auxiliary function, rl_variable_value, returns
    a string corresponding to a readline variable's value.

g.  When parsing inputrc files and variable binding commands, the parser
    strips trailing whitespace from values assigned to boolean variables
    before checking them.

h.  A new external application-controllable variable that allows the LINES
    and COLUMNS environment variables to set the window size regardless of
    what the kernel returns.