Make JS source maps external.

* add exorcist to externalize js source maps
* update write dest for gulp-sourcemaps.

This speeds up the loading of source maps in the browser by an order of
magnitude.  Don't know why.  For #9.

lib/js-recipe.js

@@ -27,9 +27,11 @@ var gulpUglify = require('gulp-uglify');
 var gulpUtil = require('gulp-util');
 var map = require('map-stream');
 var notifier = require('node-notifier');
+var path = require('path');
 
 // Optional deps:
 var browserify = require('browserify');
+var exorcist = require('exorcist');
 var gulpBrowserify = require('gulp-browserify');
 var gulpJshint = require('gulp-jshint');
 var gulpNgAnnotate = require('gulp-ng-annotate');
@@ -128,6 +130,8 @@ function jsBase (src, out, dest, options, watch) {
     // Browserify stream:
     if (options.browserify) {
       js = bundler.bundle()
+        // Exorcise the source maps:
+        .pipe(exorcist(path.join(dest, out + '.map')))
         // Log errors if they happen
         .on('error', function (e) {
           var title = 'Browserify Error';
@@ -148,7 +152,7 @@ function jsBase (src, out, dest, options, watch) {
       }
       js = js.pipe(gulpConcat(out));
       if (options.sourcemaps) {
-        js = js.pipe(gulpSourcemaps.write());
+        js = js.pipe(gulpSourcemaps.write(dest));
       }
     }
     return js;

package.json

@@ -57,6 +57,7 @@
     "mkdirp": "^0.5.0",
     "less-imports": "^1.1.0",
     "vinyl-buffer": "^1.0.0",
-    "node-notifier": "^4.0.2"
+    "node-notifier": "^4.0.2",
+    "exorcist": "^0.1.6"
   }
 }