Improve error boundary styles, provide way to clear browser data

app/soapbox/components/error_boundary.js

@@ -22,6 +22,11 @@ export default class ErrorBoundary extends React.PureComponent {
     });
   }
 
+  clearCookies = e => {
+    localStorage.clear();
+    sessionStorage.clear();
+  }
+
   render() {
     const { hasError } = this.state;
 
@@ -32,8 +37,26 @@ export default class ErrorBoundary extends React.PureComponent {
     return (
       <div className='error-boundary'>
         <div>
+          <i className='fa fa-frown-o' aria-hidden='true' />
           <FormattedMessage id='alert.unexpected.message' defaultMessage='An unexpected error occurred.' />
-          <a href='/'>Return Home</a>
+          <a href='/' className='return-home'>
+            <i className='fa fa-reply' aria-hidden='true' />&nbsp;
+            <FormattedMessage id='alert.unexpected.return_home' defaultMessage='Return Home' />
+          </a>
+          <p className='help-text'>
+            <FormattedMessage
+              id='alert.unexpected.help_text'
+              defaultMessage='If the problem persists, please notify a site admin with a screenshot and information about your web browser. You may also {clear_cookies} (this will log you out).'
+              values={{ clear_cookies: (
+                <a href='/' onClick={this.clearCookies}>
+                  <FormattedMessage
+                    id='alert.unexpected.clear_cookies'
+                    defaultMessage='clear cookies and browser data'
+                  />
+                </a>
+              ) }}
+            />
+          </p>
         </div>
       </div>
     );