settings: Stop serving zxcvbn from node_modules/.

Now that we have the minified_source_filenames feature, we don't need
to serve zxcvbn from node_modules/ directly to avoid re-minifying it.

Moving this this allows us to stop shipping the (duplicate)
node_modules directory in release tarballs, which will save many
megabytes of unnecessary increase in our release tarball size.

static/js/settings.js

@@ -211,7 +211,13 @@ function _setup_page() {
         if (page_params.password_auth_enabled !== false) {
             // zxcvbn.js is pretty big, and is only needed on password
             // change, so load it asynchronously.
-            $.getScript('/static/node_modules/zxcvbn/dist/zxcvbn.js', function () {
+            var zxcvbn_path = '/static/min/zxcvbn.js';
+            if (page_params.development_environment) {
+                // Usually the Django templates handle this path stuff
+                // for us, but in this case we need to hardcode it.
+                zxcvbn_path = '/static/node_modules/zxcvbn/dist/zxcvbn.js';
+            }
+            $.getScript(zxcvbn_path, function () {
                 $('#pw_strength .bar').removeClass("fade");
             });
         }

templates/zerver/register.html

@@ -8,7 +8,7 @@ Form is validated both client-side using jquery-validate (see signup.js) and ser
 
 {% block customhead %}
 {{ super() }}
-<script type="text/javascript" src="/static/node_modules/zxcvbn/dist/zxcvbn.js"></script>
+{{ minified_js('zxcvbn')|safe }}
 {% endblock %}
 
 {% block portico_content %}

templates/zerver/reset_confirm.html

@@ -1,7 +1,7 @@
 {% extends "zerver/portico_signup.html" %}
 {% block customhead %}
 {{ super() }}
-<script type="text/javascript" src="/static/node_modules/zxcvbn/dist/zxcvbn.js"></script>
+{{ minified_js('zxcvbn')|safe }}
 {% endblock %}
 
 {% block portico_content %}

zproject/settings.py

@@ -754,6 +754,13 @@ JS_SPECS = {
         ],
         'output_filename': 'min/signup.js'
     },
+    'zxcvbn': {
+        'source_filenames': [],
+        'minifed_source_filenames': [
+            'node_modules/zxcvbn/dist/zxcvbn.js',
+        ],
+        'output_filename': 'min/zxcvbn.js'
+    },
     'api': {
         'source_filenames': ['js/portico/api.js'],
         'output_filename': 'min/api.js'