Force reload of CSS/JS after running rebuildMenuAndCaches

I observed a weird phenomenon with /civicrm/profile-editor. On my localhost, it works fine. On sandbox.drupal.civicrm.org, it works if I use Firefox and Cmd-Shft-R, but otherwise it doesn't work. However, when I hacked CRM_Core_Resources to make the URLs arbitrarily different, it suddenly worked again. I believe that an overly zealous HTTP cache prevents reloading.

In many applications (including Drupal), this is solved by appending a revision-code or nonce-value to CSS/JS URLs. The revision-code should be changed whenever new code is deployed. We don't exactly receive a hook whenever a CSS/JS file is deployed, so – as a substitute – we can change the code whenever the cache is cleared.

Key changes:

• Update Resources::addScriptFile() to append the code
• Update Resources::addStyleFile() to append the code
• Update Invoke::rebuildMenuAndCaches() to change the code