Before this commit the EventEmitter methods were anonymous functions.
V8 tries to infer names for anonymous functions based on the execution
context but it frequently gets it wrong and when that happens, the
stack trace is usually confusing and unhelpful.  This commit names all
methods so V8 can fall back to the method.name property.

The above gotcha applies to all anonymous functions but is exacerbated
for EventEmitter methods because those are invoked with a plenitude of
different receivers.

Signed-off-by: Trevor Norris <trev.norris@gmail.com>

Previously if you cached process.nextTick and then require('domain')
subsequent nextTick() calls would not be caught because enqueued
functions were taking the wrong path. This keeps nextTick to a single
function reference and changes the implementation details after domain
has been required.

It's cleaner to only load domain ticker logic when the domains are being
used. This makes execution slightly quicker in both cases, and simpler
from the spinner since there is no need to check if the latest callback
requires use of domains.

Not necessary, since we can handle the error properly on the first tick
now, even if there are event listeners, etc.

Additionally, this removes the unnecessary "_needTickCallback" from
startup, since Module.loadMain() will kick off a nextTick callback right
after it runs the main module.

Fix #4856

* Callbacks from spinner now calls its own function, separate from the
  tickCallback logic
* MakeCallback will call a domain specific function if a domain is
  detected
* _tickCallback assumes no domains, until nextTick receives a callback
  with a domain. After that _tickCallback is overridden with the domain
  specific implementation.
* _needTickCallback runs in startup() instead of nextTick (isaacs)
* Fix bug in _fatalException where exit would be called twice (isaacs)
* Process.domain has a default value of null
* Manually track nextTickQueue.length (will be useful later)
* Update tests to reflect internal api changes

This reverts commit 0109a9f90acdfdb287436676f2384f7b072fbb6a.

Also included:  Port all the changes to process._makeCallback into the
C++ version.  Immediate nextTick, etc.

This yields a slight boost in several benchmarks.  V8 is optimizing and
deoptimizing process._makeCallback repeatedly.

Fix #3555