dynamically require gulp files

gulpfile.js

@@ -28,6 +28,7 @@ const _ = require('underscore');
 const assign = require('object-assign');
 const monacodts = require('./build/monaco/api');
 const fs = require('fs');
+const glob = require('glob');
 
 const rootDir = path.join(__dirname, 'src');
 const options = require('./src/tsconfig.json').compilerOptions;
@@ -256,7 +257,6 @@ gulp.task('mixin', function () {
 		.pipe(gulp.dest('.'));
 });
 
-require('./build/gulpfile.hygiene');
-require('./build/gulpfile.vscode');
-require('./build/gulpfile.editor');
-require('./build/gulpfile.extensions');
+const build = path.join(__dirname, 'build');
+glob.sync('gulpfile.*.js', { cwd: build })
+	.forEach(f => require(`./build/${ f }`));