Pass file information along to transform functions.

 - This is useful for times when you want dynamically transform files based on some logic.  For example, you're copying a file hierarchy, and want to instrument javascript files for code coverage, and compress images.

lib/ncp.js

@@ -90,7 +90,7 @@ function ncp (source, dest, options, callback) {
     var readStream = fs.createReadStream(file.name),
         writeStream = fs.createWriteStream(target, { mode: file.mode });
     if(transform) {
-      transform(readStream, writeStream);
+      transform(readStream, writeStream,file);
     } else {
       readStream.pipe(writeStream);
     }