top: change default allow/suppress define for SIGWINCH

top: change default allow/suppress define for SIGWINCH

No top #define is enabled and that constitutes default
behavior. So whenever a default behavior should change
the define must be changed too if it is to remain off.

This commit simply changes top's default behavior with
respect to allowing/suppressing any potential flood of
SIGWINCH during resize operations, if running under X.

Formerly top would block those signals to reduce costs
of repeated refreshes. That yields a requirement where
the user would have to provide another keystroke for a
final display update. That keystroke may not always be
needed now, but it ultimately depends on some terminal
emulator's scrollback buffer. In any case, the cost of
re-sizing may go up a bit, under most window managers.

(everything is perfectly justified plus right margins)
(are completely filled, but of course it must be luck)

Reference(s):
commit 4f33b6b8c56464b4044deb29a3bb0e32622e108f
http://www.freelists.org/post/procps/top-won-the-sigwinch-war
http://www.freelists.org/post/procps/top-won-the-sigwinch-war,4
http://www.freelists.org/post/procps/top-won-the-sigwinch-war,5

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