stream_wrap: add HandleScope's in uv callbacks
Ensure that no handles will leak into global HandleScope by adding
HandleScope's in all JS-calling libuv callbacks in stream_wrap.cc.
Fix: https://github.com/iojs/io.js/issues/1075
NOTE: WIP
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Ensure that no handles will leak into global HandleScope by adding
HandleScope's in all JS-calling libuv callbacks in stream_wrap.cc.
Fix: https://github.com/iojs/io.js/issues/1075
NOTE: WIP