Adding new PivotByDimension DataTable filter that can pivot a report by (almost) any dimension. The filter can pivot reports by their subtable dimension and can also pivot by other dimensions (by using segments).

Notes:

- in the UI, only pivoting by subtable is supported
- change to CSV DataTable renderer so column names w/ commas & quotes can appear in text
- change to XML DataTable renderer so column names w/ invalid XML characters can be rendered (bit of an iffy change, XML format needs an overhaul I think)
- includes new config option 'pivot_by_filter_enable_fetch_by_segment'
- includes additions to component metadata classes (ie, Report/Dimension)

Piwik is a free/libre analytics platform. Refs #4455 GNU Package requirement to use free/libre instead of open source

 * updating all variables/methods containing Referers
 * RENAMING custom segments definition, and custom scheduled reports definition, so that when they load "Referers" segment/report it still works as expected
 * RENAMING old archived data so that archived blobs are called Referrers
  * Reverting part of 0deb2bbb
  * Update integration tests generating PDF+HTML with images on my dev box (GD 2.1 and PHP 5.5)

Refs #4059 Work in progress: Conversion to use Namespaces: Period*, Metrics, Segment, SegmentExpression, PluginsManager.
Removed some deprecated code.

Converting Piwik core source files, PHP, JS, TPL, CSS

More info: http://piwik.org/participate/coding-standards/

git-svn-id: http://dev.piwik.org/svn/trunk@7648 59fd770c-687e-43c8-a1e3-f5a4ff64c105

Notes:

  * Modified renderers so they would render arrays better. Before, arrays were added to DataTables and array keys were either lost or ignored, now they are rendered.
  * Fixed issue w/ JSON rendering that rendered arrays when the PHP arrays didn't have contiguous keys.
  * Augmented some exception messages.
  * Added utility method processRequest to Piwik_API_Request to ease use of the class.


git-svn-id: http://dev.piwik.org/svn/trunk@7612 59fd770c-687e-43c8-a1e3-f5a4ff64c105

git-svn-id: http://dev.piwik.org/svn/trunk@6669 59fd770c-687e-43c8-a1e3-f5a4ff64c105

git-svn-id: http://dev.piwik.org/svn/trunk@6498 59fd770c-687e-43c8-a1e3-f5a4ff64c105