Factoring out archiving Custom variables + cleaning it up (breaking down huge archiveDay function into several methods)

Renaming some core code to make sense (sumMetrics and makeEmptyRow instead of ugly names)

TODO: continue with other plugins

Fixes #1899, add report that merges all Referrer reports and modified Referrer overview report to support subtables for each referrer type.

Notes:
- modified VisualPHPUnit so Incomplete errors that come from missing expected files have 'Use Processed' link option.
- fixed bug in VisualPHPUnit's 'Use Processed' link (a piwik-specific change).
- Added ability to prepend/append HTML to labels in HTML datatable output by using html_label_prefix/html_label_suffix.
- Fix bug in Piwik_DataTable_Array::mergeSubtables where keyName was not copied in new array.



git-svn-id: http://dev.piwik.org/svn/trunk@7830 59fd770c-687e-43c8-a1e3-f5a4ff64c105

git-svn-id: http://dev.piwik.org/svn/trunk@7254 59fd770c-687e-43c8-a1e3-f5a4ff64c105

git-svn-id: http://dev.piwik.org/svn/trunk@5575 59fd770c-687e-43c8-a1e3-f5a4ff64c105

 * Stop aggregating visits for Custom variables of scope "page"
  * still OK for scope "visit" since there is supposed to be one custom var value per custom variable name for a given visit
 * Now we always display the Actions columns so that these rows with no visit still show the number of Actions
 * cleaned up from custom var output report, removed some "price_viewed" column left out

UI Change (future FAQ maybe...)
 * When there is a "Visits" column for the Custom Variable report with a value of "-" (hyphen) then it means this custom variable was used with scope=page. 

Fixes #2662
 * Added integration tests testing getPageUrl with multiple periods and websites 
 * fixed a bug when idSite=all or 1,2,3

git-svn-id: http://dev.piwik.org/svn/trunk@5235 59fd770c-687e-43c8-a1e3-f5a4ff64c105

git-svn-id: http://dev.piwik.org/svn/trunk@5172 59fd770c-687e-43c8-a1e3-f5a4ff64c105

 * Adding Product page/Category page view tracking via Tracking function: setEcommerceView: function(sku, name, category)
This is using the Custom Variables per page, using slot 3/4/5 to track sku/name/category
 * UPdated PHP tracker + JS tracker + adding tests
 * Items reports (best SKU/Name/Category) will automatically call the Custom Vars API and enrich the items reports with "Visits", "Conversion rate"
 * Updating integration tests + fixing bug when item is deleted from Cart, then added again (or purchased)


git-svn-id: http://dev.piwik.org/svn/trunk@4723 59fd770c-687e-43c8-a1e3-f5a4ff64c105