sort system tables in test-cleandb and fix typo in config
Reload the registry when a table / bucket is not found

Fixes: https://phabricator.wikimedia.org/T76492
Generalize registry reloading & start introducing HTTPError

- Generalize registry reloading to most operations in storage.js
- Add an HTTPError class in rbUtil (renamed from util to avoid clashes with
  node's util module), and handle it in server.js
- Separate out response handling in server.js
- Disable a previously falsely passing test (which used baseURL instead of
  bucketURL). We don't fetch wikitext (yet), so don't test for it.

Fixes: https://phabricator.wikimedia.org/T76492
Starts fixing: https://phabricator.wikimedia.org/T76693
Add rudimentary mechanism for injecting CORS headers
Move CORS logic out of restbase.js and into server.js
Remove changes to restbase.js
Merge pull request #68 from hardikj/config-fix

sort system tables first in test-cleandb and fix typo in config
Merge CORS handling branch

- Integrate the CORS headers into the generic handleResponse method
- Add comment to disabled proxy handler test
Merge remote-tracking branch 'wikimedia/master'