Merge branch 'master' of github.com:simplesamlphp/simplesamlphp

# By Brian Vuyk
# Via Brian Vuyk (1) and Jaime Pérez Crespo (1)
* 'master' of github.com:simplesamlphp/simplesamlphp:
  Use !in_array() for improved readability
  Add support for sender-vouches