Simplify Mac package creation

QGCInstaller.pri

@@ -31,8 +31,9 @@ installer {
         # macdeploy is missing some relocations once in a while. "Fix" it:
         QMAKE_POST_LINK += && python $$BASEDIR/tools/osxrelocator.py $${TARGET}.app/Contents @rpath @executable_path/../Frameworks -r > /dev/null 2>&1
         # Create package
-        QMAKE_POST_LINK += && cd $${OUT_PWD}
-        QMAKE_POST_LINK += && hdiutil create -verbose -stretch 4g -layout SPUD -srcfolder $${DESTDIR}/$${TARGET}.app -volname $${TARGET} $${DESTDIR}/package/$${TARGET}.dmg
+        QMAKE_POST_LINK += && hdiutil create /tmp/tmp.dmg -ov -volname "$${TARGET}-$${MAC_VERSION}" -fs HFS+ -srcfolder "$${DESTDIR}/"
+        QMAKE_POST_LINK += && hdiutil convert /tmp/tmp.dmg -format UDBZ -o $${DESTDIR}/package/$${TARGET}.dmg
+        QMAKE_POST_LINK += && rm /tmp/tmp.dmg
     }
     WindowsBuild {
         QMAKE_POST_LINK += $$escape_expand(\\n) cd $$BASEDIR_WIN && $$quote("\"C:\\Program Files \(x86\)\\NSIS\\makensis.exe\"" /DINSTALLER_ICON="\"$${QGC_INSTALLER_ICON}\"" /DHEADER_BITMAP="\"$${QGC_INSTALLER_HEADER_BITMAP}\"" /DAPPNAME="\"$${QGC_APP_NAME}\"" /DEXENAME="\"$${TARGET}\"" /DORGNAME="\"$${QGC_ORG_NAME}\"" /DDESTDIR=$${DESTDIR} /NOCD "\"/XOutFile $${DESTDIR_WIN}\\$${TARGET}-installer.exe\"" "$$BASEDIR_WIN\\deploy\\qgroundcontrol_installer.nsi")