Fix helper process_new_notifier(), etc.  to nil-check argument

app/helpers/application_helper.rb
- Fix to nil-check the argument for both process_new_notifier()
  and process_emphasizer().
Modify not to display link to change password, etc. if current_user is anonymous

app/models/user.rb
- Add anonymous?().
app/views/layouts/application.html.erb
- Modify not to display link to change password if current_user
  is anonymous.
app/views/projects/show.html.erb
- Modify not to display form to enter new progress if current_user
  is anonymous.