src: don't lazy-load timer globals

[bnoordhuis]

Don't lazy-load setInterval(), setTimeout(), etc. Most applications are
going to need them and routing every call through NativeModule.require()
and Function#apply() is not exactly efficient.

R=@trevnorris?

https://jenkins-iojs.nodesource.com/view/iojs/job/iojs+any-pr+multi/382/

[Fishrock123]

LGTM

[petkaantonov]

Function#apply() is not exactly efficient

just a side note: this was using .apply in the one and only way v8 recognizes and optimizes for, that is .apply(x, arguments) :p

[bnoordhuis]

Sure, but it's still less efficient than calling the function directly.

[targos]

What about lazy-loading the functions only on first call ?

global.setTimeout = function() {
  var t = NativeModule.require('timers');
  global.setTimeout = t.setTimeout;
  return t.setTimeout.apply(this, arguments);
};

[bnoordhuis]

What good would that do? This PR is based off the observation that the timers module is almost certainly going to get loaded anyway (by core, if not the user) so you might as well do it eagerly.