Refactored ViewDataTable::getRequestString to return an array so building a URL is not necessary. Also changed request_string_suffix view property to request_parameters_to_modify.

Refs #4041, fix bug in displaying DBStats reports by redefining how columns_to_display view property defaults and allow unique visitors to be displayed on reports that have it, outside of period=day.

Fix regression causing un-flatten option to not be shown (custom parameters have lower priority than existing query parameters).

Refs #4040, #4041, move all ViewDataTable properties to the viewProperties array and allow these properties to be specified through new display metadata. Converted the Actions, Goals, UserSettings and VisitTime controllers.

Notes:
  - Includes refactoring of ExcludeLowPopulation filter.

Allow extra query params to be added to ViewDataTable's API request string and remove  modification hack in Goals::getItemsView.

Rename ViewDataTable::setDataTableType/getDefaultDataTableType to setDataTableCssClass/getDefaultDataTableCssClass and move newly added view data to viewProperties member.

Refs #4041, allow subtable template to be used if idSubtable is in request so Actions controller doesn't have to call setTemplate. Also did some mild refactoring for Piwik_ViewDataTable_HtmlTable::setRecursiveLoadDataTableIfSearchingForPattern.

Modified _dataTable.twig to use a Piwik_DataTable instance instead of a DataTable converted to an array, allowed HtmlTables to render expanded DataTables, and removed @CoreHome/_dataTableActions_recursive.twig.

- Remove uniqIdTable, chartDivId and related code as important element IDs are determined in datatable_manager.js now.
- Clarify _dataTable twig template + related css.
- Also added visiblity to Piwik_DataTable_Renderer_Php::renderException.

Fix bug in referrers index.twig. Check that '...Percent' variables are defined before checking if not empty.

Notes:
  - Modified ManySitesImportedLogs fixture to add segments if desired.
  - Switch to synchronous execution of curl requests until deadlocking issue in archive processing is dealt with.
  - Fixed bug in LogAggregator where if a segment required a subquery, archiving would failed.

Allow aspects of the testing environment to be init-ed by setting globals so it is not required to include of all of Piwik.

Make Piwik_Access a singleton instance and remove use of Zend_Registry for the Piwik_Access singleton.