qt5-qtbase both replaced by and conflicts with qt56-qtbase on 10.7

[michaelld (Michael Dickens)]

I just updated 'port' on my 10.7 Mac OS X install; no libc++, but trying to use MacPorts Clang 4.0 where possible since it seems to work pretty well. When I do "port info qt5-qtbase", I get back:

% port info qt5-qtbase
qt5-qtbase @5.7.1 (aqua)
Replaced by:          qt56-qtbase
Variants:             debug, examples, gstreamer, [+]openssl, pulseaudio, tests,
                      universal

Description:          Tools and Module(s) for Qt Tool Kit 5: Qt Gui, Qt Widgets,
                      Qt Print Support, Qt OpenGL, Qt Core, Qt XML, Qt SQL, Qt
                      Network, Qt Test, Qt D-Bus, Qt Concurrent, and Qt Platform
                      Headers
Homepage:             http://qt.io

Extract Dependencies: xz
Build Dependencies:   pkgconfig, gawk, clang-4.0
Library Dependencies: zlib, libpng, jpeg, fontconfig, freetype, dbus, tiff,
                      libmng, glib2, icu, pcre, libiconv, harfbuzz, openssl
Conflicts with:       qt3, qt3-mac, qt56-qtbase, qt55-qtbase
Platforms:            macosx
License:              {LGPL-3 GPL-3 OpenSSLException}
Maintainers:          Email: mcalhoun@macports.org
                      Policy: openmaintainer
%

which has the issue that it is both "replace_by" as well as "conflicts with" qt56-qtbase.

[MarcusCalhoun-Lopez (Marcus Calhoun-Lopez)]

In f673a61a68136ccbd7588898ae7a50e3dbaf8260/macports-ports:

qt5, qt56: do not conflict when qt56 replaces qt5

Fixes #53826