More API cleanup.

* Removed String::Empty, Number::New, Integer::New, Integer::NewFromUnsigned, FunctionTemplate::New and Object::New without Isolate* parameter.

* Removed Integer::New and Integer::NewUnsigned with weird argument order.

Chrome CLs matching this change are prepared, BTW.

LOG=y
BUG=324225
R=dcarney@chromium.org

Review URL: https://codereview.chromium.org/118523003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@18383 ce2b1a6d-e550-0410-aec6-3dcde31c8c00