piwik 6.x-2.1

Maintenance release with some important changes and fixes.

New features:
* Added domain mode settings / What are you tracking?
* Added custom variables support
* SiteSearch tracking is now working
* #936684: Exclude roles from tracking
* #1055980: Implement DoNotTrack privacy feature

Bugfixes:
* Move piwik.test file to module root
* Re-order fieldsets from general to more specific from top down
* Added updated and extended tests
* Corrected DNT description
* Don't rawdecode or & don't get encoded
* D7 code style cleanup
* Custom variables names and values can be 100 chars long
* Moved custom vars before codesnippet_before
* Added SiteSearch_Results counter
* Added setCustomData for search result counter
* Fixed all CustomUrls to be absolute
* Updated readme for custom variables
* Remove dead and outdated CustomVariables code
* Updated 403/404 tracking urls
* Changed internal variables
* Added setCustomUrl()
* Fixed incorrect use of setDocumentTitle() with setCustomUrl()
* Removed translation directories
* More rows in pages list
* Rename piwik_visibility variable to piwik_visibility_pages for consistency.
* Better vertical tabs summary
* Typo in variable name
* #1056924: Exclude batches from tracking