Fixes some sed errors introduced in c43cfe.
Unfortunately moving libdeno required splitting build.rs into two parts,
one for cli and one for core.
I've also removed the arm64 build - it's complicating things at this
re-org and we're not even testing it. I need to swing back to it and get
tools/test.py running for it.
- Improves speed and binary size significantly.
- Makes deno_last_exception() output a JSON structure.
- Isolate::execute and Isolate::event_loop now return
structured, mapped JSError objects on errors.
- Removes libdeno functions:
libdeno.setGlobalErrorHandler()
libdeno.setPromiseRejectHandler()
libdeno.setPromiseErrorExaminer()
In collaboration with Ryan Dahl.
