CociLoader added
Merge https://github.com/maitbayev/cms

* https://github.com/maitbayev/cms:
  Make headers available in compilation sandbox for Communication
  Show server time in per-contest or per-user timezone (as defined in DB)
  Typo in a CWS template
  Improve sample nginx.conf by using keep-alive connections to backends
  Fix a couple of comments
  Improve argument parsing
  Fix tests
  Do not use explicit casts to str
  Fix some remaining uses of open instead of io.open
  Finish adding `from __future__ import unicode_literals` to all files
  nginx: correctly mangle Location URL for RWS.
  Fix service killing from AWS.