(In [2814]) quick fixes #1529 - recovers more gracefully if glob() is disabled; installer can be run, and it will provide a warning.
Piwik will continue to run albeit in a crippled state:
(In [2815]) refs #1529 - glob is critical for running updates; making this an installation blocker instead
(In [2817]) refs #1529 - added/tested replacement glob() function; a missing glob() is still a warning