Add ability to pass through transform plugins to browserify.

ts/gulpbrowser.browserify.ts

@@ -2,7 +2,12 @@
 import plugins = require("./gulpbrowser.plugins");
 
 
-let browserify =  function() {
+let browserify =  function(transforms) {
+
+    transforms = transforms || [];
+    if (typeof transforms === 'function') {
+        transforms = [transforms];
+    }
 
     let forEach = function(file, enc, cb){ // do this with every chunk (file in gulp terms)
 
@@ -18,8 +23,17 @@ let browserify =  function() {
         };
 
         if(file.contents.length > 0){
-            plugins.browserify(file, { basedir: file.base })
-                .bundle(bundleCallback);
+            let browserified = plugins.browserify(file, { basedir: file.base });
+
+            transforms.forEach(function (transform) {
+                if (typeof transform === 'function') {
+                    browserified.transform(transform);
+                } else {
+                    browserified.transform(transform.transform, transform.options);
+                }
+            });
+
+            browserified.bundle(bundleCallback);
         } else {
             plugins.beautylog.warn("gulp-browser: .browserify() file.contents appears to be empty");
             cb(null,file);