Bug 905493.  Fix setting document.location via an Xray to not enter the content compartment.  r=peterv
Bug 920125.  getOwnPropertyDescriptor on Xrays for DOM interface and prototype objects should actually work.  r=peterv
Bug 919603 part 1.  Introduce support for the [Global] extended attribute.  r=peterv
Bug 919603 part 2.  Change this-handling in codegen to only do the special global object stuff on interfaces where it might matter.  r=peterv