Property attribute control API

Object.create(p,{(n:attrs)*})

  .defineProperty(o,n,attrs)

  .defineProperties(o,{(n:attrs)*})

  .getOwnPropertyNames(o) → names

  .getOwnPropertyDescriptor(o,n) → attrs

  .freeze(o) → o

attrs ::= { value:v,

writable:b,       enumerable:b,

configurable:b } | …