cares_wrap: don't set oncomplete property from c++

Don't set the oncomplete property in src/cares_wrap.cc, we can do it
just as easily in lib/dns.js.

Switch two closures to the 'function with _this_ object' model. Makes
it impossible for an overzealous closure to capture too much context
and accidentally hold on to too much memory.
cares_wrap: remove unused function getHostByName()

Hasn't been used in ages. Also remove its (already disabled) test.
src: centralize class wrap/unwrap

While almost all cases were handled by simple WRAP/UNWRAP macros, this
extends those to cover all known occurrences.
src: don't obj->Set(Integer::New(...), val)

Don't create an Integer when setting a numeric index on an object or an
array, use the version of v8::Object::Set() that takes an uint32_t.

Change the types of the variables from int to uint32_t and clean up
some code consistency issues while we're here.
src: fix build break from generic macro name

WRAP is too generic a macro name and causes the build to fail from
conflicts. They have been prepended with NODE_.
crypto: remove two unused static variables
util: fix isPrimitive check

Previous check failed for the edge case Object.create(null). This uses
the current v8 code for the check.
crypto: use consistent variable names

Code cleanup: don't call a Connection object `p` in some places, `c` in
other places and `ss` in yet other places. Let's just call it `conn`.

This also fixes about a million style errors in one fell swoop.
crypto: use consistent conn object unwrapping

We use `Foo:Unwrap(args.This())` everywhere else, let's use the same
idiom for Connection::Unwrap().
crypto: add TLS 1.1 and 1.2 to secureProtocol list
src: move ReqWrap::data_ to FSReqWrap

FSReqWrap is the only ReqWrap child class that uses the data_ field so
move it out of ReqWrap and into FSReqWrap.
src: clean up FSReqWrap

Move the 'free FSReqWrap data?' logic into the class itself.
src: remove redundant symbol init in node_file.cc

Don't lazy-init the oncomplete symbol string in the After() function,
it has already been created at module init time.
http: speed up callbacks, use array indices

Use array indices rather than named properties to store callbacks on
the HTTPParser object.  Speeds up the http benchmarks by a few percent.
tls: handle errors on socket before releasing it

Fix sudden uncatchable ECONNRESETs, when using https server.