Add debug log which print amount of used memory.
refs #6075 added a bit of documentation
Refactor to reuse Piwik components.
Merge branch 'master' of github.com:piwik/piwik
refs #5144 better fix for array to string to conversion.

Noticed this hack while I worked on the tracker refactoring. Dispatch
should always return a string. Fixing the problem where it actually occurs.
An even better fix would be not to support serialize=0 for format PHP as
it is meant only for internal requests. If someone wants to access data
serialize=1 should be set.
the redis section is not needed anymore
Merge pull request #6794 from czolnowski/6708-provide-better-information-of-memory-usage-in-archiving

Provide better information regarding memory usage by each plugin
Fixes #6562
Fixes #6806, correctly set default for viewDataTable query parameter in ViewDataTable\Factory::build(). If forceDefault is true, priority is function specified default, saved value, and report configured default. If not true, saved value, function specified default, report configured default.
updated submodule
include server time (as timestamp) in visitor actions (visitor live API)