deps: upgrade libuv to 7841f77
deps: upgrade libuv to e4d8cba
http: close connection on 304 and chunked encoding

Force the connection to close when the response is a 304 Not Modified
and the user has set a "Transfer-Encoding: chunked" header.

RFC 2616 mandates that 304 responses MUST NOT have a body but node.js
used to send out a zero chunk anyway to accommodate clients that don't
have special handling for 304 responses.

It was pointed out that this might confuse reverse proxies to the point
of creating security liabilities, so suppress the zero chunk and force
the connection to close.
buffer: remove float write range checks

Removed range checks when writing float values, and removed a few
includes and defines. Also updated api docs to reflect that invalid 32
bit float is an unspecified behavior.
build: Add some gyp artifacts to .gitignore
http: close connection on 204 and chunked encoding

This is similar to commit 2cbf458 but this time for 204 No Content
instead of 304 Not Modified responses.

When the user sends a 204 response with a Transfer-Encoding: chunked
header, suppress sending the zero chunk and force the connection to
close.
gitignore: ignore v8.log files
tls: make slab buffer's size configurable

see #4636