Visual options definitions

[Warren Block]

Defining port options through variables makes it somewhat hard to 
visualize.  Could we consider a visual definition?

OPTIONS_VISUAL=			\
/* normal options */		\
FOO "Build with Foo support"	\
BAR "Runtime BAR support"	\
/* only one */			\
radio[				\
   A "Use A for something"	\
   B "Use B instead"		\
   C "Use C instead of A or B"	\
]				\
/* at least one */		\
multi[				\
   X "Include X support"		\
   Y "Include Y support"		\
   Z "Include Z support"		\
]				\
/* zero or more */		\
group[				\
   H "Use H for something"	\
   I "Use I for something"	\
   J "Use J for something"	\
]

The [] delimiters and C-style comments are arbitrary, just what I tried 
that does not conflict with normal make(1) syntax.

The description of standard definitions could be left empty, to get a 
default value:

[NLS] ""

This would all be parsed into the normal OPTIONS variables, so either 
style of options definitions could be used and no other changes would 
need to be made.