* nsf.c (AliasGet): Plumbing a memleak found by valgrind. The computed Tcl_Obj from AliasIndex must be refcount-managed explicitly, otherwise the path via AliasGet leaks it.
* nsf.c (ParamOptionParse), nsfInt.h: Provide for own MAX and MIN macros, the ones reused implicitly from Tcl's tommath have vanished in 8.7 branches; and are not provided otherwise, at least in MinGW settings. Fixes 8.7 builds for MinGW under Win.