top: scale length for new graphs to a terminal's width
When the beginning of the Mem/Swap graphs was variable
scaling them to the current terminal's width was a bit
of a costly nightmare. So the graph size was fixed and
subject to truncation. However now that the start of a
graph can be easily predicted, I've revisited scaling.
As it turns out, any cost is minimal & mostly incurred
at an opportune time, at SIGWINCH or user interaction.
Plus, most of the apparent arithmetic is actually just
a means of documenting and will disappear thru compile
time constants in the ultimate generated machine code.
Note: those graphs will now behave just like any other
Summary Area element - they will scale from full sized
down to a terminal width of 80 columns, at which point
those displayed graphs are then subject to truncation.
Signed-off-by: Jim Warner <james.warner@comcast.net>