top: provide the means to adjust scaled process memory

This commit is an unrequested outgrowth of the earlier
change dealing with summary area memory field scaling.
That user selectable scaling provision is now extended
to include 6 (at present) task oriented memory fields.

The new companion 'e' (lower case) interactive command
has been added and, like the 'E' command, it can cycle
each of the currently displayed memory columns between
KiB through TiB. There are, however, some differences.

Where '+' indicates summary area truncation at a given
radix, task memory fields are automatically scaled for
their column. Thus, not all rows use the same scaling.

And, while summary area field widths were not changed,
the task memory columns were widened in order to offer
more meaningful data when the radix was increased. The
precision is automatically increased in step with each
radix: MiB displays 2 decimal places, GiB 3 and TiB 4.

To compliment that additional precision, both the %CPU
and %MEM fields were widened by 1 column and now offer
precision up to 3 decimal places. But, unique to %CPU,
widening could already have occurred due to the number
of processors in some massively parallel boxes. At any
rate, total extra width for both memory and percentage
fields could amount to twenty (precious) columns more.

So for both the memory and % fields the original width
(along with loss of precision) can be restored via new
compiler conditionals which this commit also provides.

p.s. and it will be rcfile preserved for any restarts!

(now that we know a '.' + 2 spaces is squeezed to one)
(everything's perfectly justified, but it's just luck)

Reference(s):
http://www.freelists.org/post/procps/top-regression-reports

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

top/top_nls.c

@@ -458,7 +458,7 @@ static void build_uniq_nlstab (void) {
       "Help for Interactive Commands~2 - %s\n"
       "Window ~1%s~6: ~1Cumulative mode ~3%s~2.  ~1System~6: ~1Delay ~3%.1f secs~2; ~1Secure mode ~3%s~2.\n"
       "\n"
-      "  Z~5,~1B~5,E     Global: '~1Z~2' color mappings; '~1B~2' bold; '~1E~2' summary mem scale\n"
+      "  Z~5,~1B~5,E,e   Global: '~1Z~2' colors; '~1B~2' bold; '~1E~2'/'~1e~2' summary/task memory scale\n"
       "  l,t,m     Toggle Summaries: '~1l~2' load avg; '~1t~2' task/cpu stats; '~1m~2' mem info\n"
       "  1,I       Toggle SMP view: '~11~2' single/separate states; '~1I~2' Irix/Solaris mode\n"
       "  f,F,X     Fields: '~1f~2'/'~1F~2' add/remove/order/sort; '~1X~2' increase fixed-width\n"