win,node-gyp: allow node.exe/iojs.exe to be renamed

On Windows, when node or io.js attempts to dynamically load a compiled
addon, the compiled addon tries to load node.exe or iojs.exe again -
depending on which import library the module used when it was linked.
This makes it impossible to rename node.exe or iojs.exe, because when
that happens the module can't find its dependencies.

With this patch, a delay-load hook is added to all modules that are
compiled with node-gyp. The delay-load hook ensures that whenever a
module tries to load imports from node.exe/iojs.exe, it'll just refer
back to the process image, thus making it possible to rename the
iojs/node binary.

Bug: nodejs#751
Bug: nodejs#965
Upstream PR: nodejs/node-gyp#599

PR-URL: nodejs#1251
Reviewed-By: Rod Vagg <rod@vagg.org>