info - general information about unit generator descriptions

DESCRIPTION:

A list of unit generators currently available in cmusic follows.  Each
unit generator argument is described with an arbitrary name for its
function (such as "input" or "output"), and a list enclosed in square
brakets which indicates the allowable argument types:

    b = io block,
    p = note parameter,
    f = function,
    v = static variable,
    n = number (e.g., a constant or constant expression),
    d = dynamic variable.

In most cases, if an argument MAY be a "d", then it SHOULD be a "d".
An asterisk after the final right bracket indicates that the argument list
may continue indefinitely.

The code for the unit generators is in the distribution source area
in files with names like: ug.*.c and ug.*.h
