Changes in QMBF 5.51:
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Improved usability of QMBF on the OS X operating system:

- on OS X, it is now possible to use the up/down keys to navigate vertically in all tables
- on OS X, associating .mbf files with QMBF (via Finder) now works properly
- on OS X, the "Plot Options" dialog will now be shown in the "Plot" menu (instead of "QMBF"->"Preferences")

The changes in this QMBF version do not have any effect under Linux.
(The C preprocessor is used to perform conditional compilation depending on the operating system.)