ConfigModifier.removePlugin should toggle off if default

lib/browser.js

@@ -12,8 +12,8 @@ module.exports = {
     PluginDependency:   require('./models/pluginDependency'),
 
     // Modifiers
-    SummaryModifier: Modifiers.Summary,
-    ConfigModifier: Modifiers.Config,
+    SummaryModifier:    Modifiers.Summary,
+    ConfigModifier:     Modifiers.Config,
 
     // Constants
     CONFIG_FILES:       require('./constants/configFiles.js'),

lib/modifiers/config/removePlugin.js

@@ -1,3 +1,5 @@
+var DEFAULT_PLUGINS = require('../../constants/defaultPlugins');
+var togglePlugin = require('./togglePlugin');
 
 /**
  * Remove a plugin from a book's configuration
@@ -8,6 +10,16 @@
 function removePlugin(config, pluginName) {
     var deps = config.getPluginDependencies();
 
+    var isDefault = DEFAULT_PLUGINS.find(function(dep) {
+        return dep.getName() === pluginName;
+    });
+
+    // For default plugin, we have to disable it instead of removing from the list
+    if (isDefault) {
+        return togglePlugin(config, pluginName, false);
+    }
+
+    // Remove the dependency from the list
     deps = deps.filter(function(dep) {
         return dep.getName() === pluginName;
     });