top: refined memory graphs two abreast summary display

top: refined memory graphs two abreast summary display

When more than two cpus are displayed per summary area
line in graph form, those memory graphs were scaled to
that same width for consistency & aesthetics. However,
they probably shouldn't have been reduced to less than
terminal width due to a resulting loss of information.

[ after all, detailed memory stats are never reduced ]

So now, supporting logic was refactored to behave just
as it did before the 4 toggle was expanded beyond '1'.

[ the changes impact the 2 memory graphs exclusively ]

Reference(s):
https://www.freelists.org/post/procps/top-enhancements-2-bugs-swatted,1

Signed-off-by: Jim Warner <james.warner@comcast.net>