mingw: document approach for integrating mingw with native packages
    
    Historically the mingw packages were introduced as completely separate
    components in Fedora, with their own spec files, separate maintainers,
    etc. This was driven primarily from a reasonable concern that the
    maintenence of MinGW builds would be an unacceptable burden on the
    existing native package maintainers.
    
    In the many years since MinGW was introduced to Fedora, however, it has
    become clear that this concern was mostly unfounded. While some packages
    may be more difficult, the majority of MinGW packages are not difficult
    to keep building successfully in Fedora. Furthermore the existance of
    MinGW support in Fedora, has enabled upstream projects to actively test
    Windows support in their CI systems prior to release.
    
    There biggest problem for MinGW packages in Fedora has turned out to be
    caused by the very decision to package them as completely separated
    components. Specifically it is difficult to ensure that MinGW builds are
    being kept in sync with changes to the native package builds, even when
    both share the same maintainer. This is particularly apparent when
    looking at reports of unaddressed CVEs in Fedora packages.
    
    With this all in mind, it is the view of the MinGW SIG that Fedora is
    best served by having MinGW support integrated into the native packages
    in general. While the specific maintainer of the native package will
    have slightly more work, history has demonstrated this is not likely to
    be significant in most cases. For Fedora maintainers in aggregate, the
    amount of effort spent on MinGW will decrease, benefiting the project
    as a whole. This proposal thus strongly promotes the integrated MinGW
    packaging approach to be the default, though existing native package
    maintainers retain the ability to decline such proposals.
    
    The concept of integrating MinGW support into the native packages has
    already been put into practice on many packages where the same Fedora
    contributor maintained both the MinGW and native packages. Specifically
    examples implemented by Sandro Mani are:
    
      mingw-eigen3
      mingw-enchant2
      mingw-freeimage
      mingw-gdal
      mingw-GeographicLib
      mingw-geos
      mingw-giflib
      mingw-gtkspell3
      mingw-gtkspellmm30
      mingw-jxrlib
      mingw-leptonica
      mingw-libgeotiff
      mingw-libimagequant
      mingw-libkml
      mingw-librttopo
      mingw-libspatialite
      mingw-libwebp
      mingw-openjpeg2
      mingw-OpenSceneGraph
      mingw-osgearth
      mingw-podofo
      mingw-proj
      mingw-python-pillow
      mingw-qtspell
      mingw-shapelib
      mingw-svg2svgt
      mingw-tesseract
      mingw-uriparser
    
    and examples by Daniel Berrange are
    
      mingw-libvirt
      mingw-gtk-vnc
      mingw-libvirt-glib
      mingw-libosinfo
      mingw-osinfo-db-tools
    
    Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>