Fixed: possible segfault with PHP 5.5
Changed: Connect to MySQL once and reconnect if needed
Changed: units added to request page
Added: Memory Peak Usage
Added: StatsD driver
Changed: configuring some INI entries only with HAVE_GETRUSAGE
Changed: per driver 'stats_enabled' flag
Changed: places where *_stats_enabled may be defined
Changed: putting getaddrinfo() for StatsD at MINIT
Fixed: event.type was too small to contain all event types
Removed: deffered processing

Deffered processing can't be easily implemented in a generic & driver
agnostic way. Depending on the drivers, some deffered processing will
happen inside them.
Changed: removed insert_request()

This must rather be done in the drivers
Changed: light refactoring (naming)
Changed: header includes cleaning
Added: socket driver