Re: file associations / positional arguments

I had to make one backward-compatibility breaking change to make this work 
satisfactorily.
Problem is that Windows filenames often do contain spaces, and that the OS, 
when you
use the "Open with..." menu item on a document, is not so friendly as to 
quote this filename.
So WinBoard will be confronted with command lines like

   winboard.exe Candidate Matches.pgn
   winboard.exe KingCheck ICS.xsf

The existing code would then complain that Matches.pgn was an invalid 
option (as only a single
positional argument would be accepted), and even if it survived that, its 
attempts to open the
file Candidate would likely come to nothing.

So I now made it such that when reading the value of a positional argument, 
spaces are not
considered a termination character, but are considered part of the arg 
value. This, however,
would break a usage like

   winboard.exe games.pgn -ncp

which in the old system would be parsed like

   winboard.exe -lgf games.pgn -ncp

but now would be interpreted as

   winboard.exe -lgf "games.pgn -ncp"

Is there any legitimate of such a mixture of position arguments and regular 
command-line options?
And even if there is, should we continue to support it?