Setting NODE_GYP_DIR for addon.gypi to setting absolute path for src/…

…win_delay_load_hook.c,

and fixes of the long relative path issue on Win32.
Fixes of #636

addon.gypi

@@ -40,7 +40,7 @@
         'conditions': [
           [ 'OS=="win"', {
             'sources': [
-              'src/win_delay_load_hook.c',
+              '$(NODE_GYP_DIR)/src/win_delay_load_hook.c',
             ],
             'msvs_settings': {
               'VCLinkerTool': {

bin/node-gyp.js

@@ -12,6 +12,7 @@ process.title = 'node-gyp'
 
 var gyp = require('../')
 var log = require('npmlog')
+var path = require("path");
 
 /**
  * Process and execute the selected commands.
@@ -20,6 +21,7 @@ var log = require('npmlog')
 var prog = gyp()
 var completed = false
 prog.parseArgv(process.argv)
+process.env['NODE_GYP_DIR'] = path.resolve(__dirname, '..');
 
 if (prog.todo.length === 0) {
   if (~process.argv.indexOf('-v') || ~process.argv.indexOf('--version')) {