Eliminate some cond-expand feature identifiers
|Reported by:||cowan||Owned by:||alexshinn|
|Component:||WG1 - Core||Keywords:|
Reduce the standardized cond-expand feature identifiers to r7rs, exact-closed, ratios, ieee-float, and full-unicode, plus the name and name-plus-version of the implementation. The others can't affect the behavior of strictly conforming programs, and it's not clear if they apply to compile time or run time on implementations that distinguish the two. See also ticket #320 for exact-complex.
Argument against: Keeping them in the standard encourages all implementations that use them to spell them the same way: darwin, not macosx.