dgram: don't assert on send('string')

Raise a TypeError when the argument to send() or sendto() is anything
but a Buffer.

Fixes the following assertion:

  $ node -e 'require("dgram").createSocket("udp4").send("BAM")'
  node: ../../src/udp_wrap.cc:220: static v8::Handle<v8::Value>
  node::UDPWrap::DoSend(const v8::Arguments&, int): Assertion
  `Buffer::HasInstance(args[0])' failed.
  Aborted (core dumped)

Fixes #4496.
object_wrap: add missing HandleScope

by Sven Panne's suggestion, see [0] for details.

[0]: https://code.google.com/p/v8/issues/detail?id=2468
npm: Upgrade to v1.2.0
typed arrays: fix 32 bit size/index overflow

Fix an out-of-bound read/write bug due to integer wrapping. Reported by
Dean McNamee.
2012.01.09, Version 0.8.17 (Stable)

* npm: Upgrade to v1.2.0
  - peerDependencies (Domenic Denicola)
  - node-gyp v0.8.2 (Nathan Rajlich)
  - Faster installs from github user/project shorthands (Nathan Zadoks)

* typed arrays: fix 32 bit size/index overflow (Ben Noordhuis)

* http: Improve performance of single-packet responses (Ben Noordhuis)

* install: fix openbsd man page location (Ben Noordhuis)

* http: bubble up parser errors to ClientRequest (Brian White)
Merge branch 'v0.8.17-release' into v0.8
Now working on 0.8.18
blog: Post about v0.8.17
blog: Add security notice to v0.8.17 post
blog: Correct shasums for v0.8.17