Prompt to restart Atom when the file system watcher setting changes

I experimented with just reloading the Window, but ran into problems. 
I'm also worried about a situation where there are multiple windows. 
Since this setting should be changed rarely, I think prompting for a 
restart is an expedient solution.

src/config-schema.js

@@ -329,7 +329,7 @@ const configSchema = {
         default: 40
       },
       fileSystemWatcher: {
-        description: 'Choose the underlying implementation used to watch for filesystem changes. Emulating changes will miss any events caused by applications other than Atom, but may help prevent crashes or freezes.',
+        description: 'Choose the underlying implementation used to watch for filesystem changes. Emulating changes will miss any events caused by applications other than Atom, but may help prevent crashes or freezes.<br>This setting will require a relaunch of Atom to take effect.',
         type: 'string',
         default: 'experimental',
         enum: [

src/main-process/atom-application.js

@@ -271,6 +271,7 @@ class AtomApplication extends EventEmitter {
       }
       this.config.onDidChange('core.titleBar', () => this.promptForRestart())
       this.config.onDidChange('core.colorProfile', () => this.promptForRestart())
+      this.config.onDidChange('core.fileSystemWatcher', () => this.promptForRestart())
     }
 
     let optionsForWindowsToOpen = []