[MacPorts] #44526: xxdiff: update to 4.0

[MacPorts]

#44526: xxdiff: update to 4.0
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  Reporter:  rjvbertin@…  |      Owner:  macports-tickets@…
      Type:  update       |     Status:  new
  Priority:  Normal       |  Milestone:
 Component:  ports        |    Version:
Resolution:               |   Keywords:  haspatch
      Port:  xxdiff       |
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Comment (by rjvbertin@…):

 It's taken a while, but here's an update that takes into account the
 latest xxdiff upstream changes and (most of?) the critiques above.
 In addition, I managed to get the application to build with Qt5 (5.4.1
 from my port:qt5-mac-devel) which allows (me :)) to use xxdiff on a remote
 X11 display too.

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Ticket URL: <https://trac.macports.org/ticket/44526#comment:11>
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