top: afford each window its own cpu/memory graph modes

When those new cpu/memory graphs modes were introduced
they had global impact. In other words, the modes that
were chosen for a 'current' window affect Summary Area
appearance for every other window as well, even though
each window sets unique View_STATES/View_MEMORY flags.

I do not know how widespread the use of top's separate
window provisions is, but I do know that documentation
promises every window (field group) provides "a unique
separately configurable summary area". And even though
that promise does not include memory scaling (separate
'E' command) the graph modes are integral to 't' & 'm'
and those were already observed on a per window basis.

So this patch just takes the cpu and memory graph mode
values out of global scope in the configuration file &
gives each window its own unique pair of graph values.

Reference(s):
commit 1d171ec741

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

top/top.1

@@ -2046,7 +2046,7 @@ Here is the general layout:
     global   # line  1: the program name/alias notation
       "      # line  2: id,altscr,irixps,delay,curwin
     per ea   # line  a: winname,fieldscur
-    window   # line  b: winflags,sortindx,maxtasks
+    window   # line  b: winflags,sortindx,maxtasks,graph modes
       "      # line  c: summclr,msgsclr,headclr,taskclr
     global   # line 15: additional miscellaneous settings
       "      # any remaining lines are devoted to the