New Features:

#890, #907- updates to Search Engines
#888 – Filtering out Bing spambot
#886 – Piwik will load bootstrap.php (if it exists) allowing for site-specific tweaks (e.g., define PIWIK_DOCUMENT_ROOT)
#870 – Add/Edit Goal UI – can now specify goal as triggered « manually »
#826 – new Tracker.knownVisitorInformation hook
#793 – rewrote sendHttpRequest enabling update notifications when allow_url_fopen is Off

Fixes:
#894 – inconsistencies between database upgrade and fresh install
#892, 893 – Length of Visits cosmetic fixes
#877 – Always start session; define PIWIK_ENABLE_SESSION_START=0 in bootstrap.php to get previous behaviour (may require increasing max number of MySQL connections)
#877 – Sites management, error in the template
#865 – unix_socket support reworked; now accepts « host », « host:port », « host:/socket/path », or « /socket/path »
#828 – session handling fix for PHP 5.2.0 (ZF1743)
#700 – Installation checks for zlib and SPL
#666 – database upgrades may take too long to run in browser
–  JSON-stringified layout was in some cases not completely decoded

Maintenance:
#911 – simplifying regular expressions
#896, #897 – all_tests.php (unit tests) broken
#876 – Piwik_Tracker_Visit should not validate $this->request in constructor

Translations:
– Minor changes across all translations.

Thanks to kolchak, kurakin, pebosi, and Uli for providing patches!