Fix npm run build when using webpack 1.12.15

'remote' module is used in electron-connect but it's removed from electron target on webpack 1.12.15.
So define 'remote' as "externals" to avoid bundling error.

http://webpack.github.io/docs/configuration.html#externals

gulpfile.js

@@ -107,7 +107,7 @@ gulp.task('webpack:browser', function() {
         __filename: false,
         __dirname: false
       },
-      target: 'electron'
+      target: 'electron-renderer'
     }))
     .pipe(gulp.dest('dist/browser/'));
 });
@@ -128,7 +128,10 @@ gulp.task('webpack:main', function() {
         __filename: false,
         __dirname: false
       },
-      target: 'electron'
+      target: 'electron-main',
+      externals: {
+        remote: true // for electron-connect
+      }
     }))
     .pipe(gulp.dest('dist/'));
 });