Port r9837 (38061af).
Port r9834 (95ac04).

Original commit message (r9834):
Also, handlify functions for loading with interceptors and callbacks.
Remove some unneeded code.  Rename Foreign::address() because it
confusingly shadows HeapObject::address() which does something quite
different.

BUG=
TEST=

Review URL: http://codereview.chromium.org/8400087
Patch from Gergely Kis <gergely@homejinni.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9844 ce2b1a6d-e550-0410-aec6-3dcde31c8c00