v0.9 Preview Snapshot for macOS

This is a temporary preview build of Mapper 0.9 for macOS. (Builds for Windows and Linux are continuously available as "unstable" downloads.) Key changes since v0.8:

• Qt 5.9.
• New OCD export (version 8-12, including georeferencing).
• Experimental support for OCD 2018 import.
• New geospatial vector data export.

Known issues:

• #1134 Saving in ocd9 and ocd10 generates broken files

Built using OpenOrienteering/superbuild@33adfe3,
cmake options:
-DCMAKE_BUILD_TYPE=Release -DUSE_SYSTEM_LIBPNG=0 -DUSE_SYSTEM_QT=0 -DMapper_GIT_TAGS=566fa81
make target:
openorienteering-mapper-git-566fa81-package