+ tests

Allow Segments to define multiple SQL columns if the segment value can be matched in any of those fields, and use to define two new segments: customVariableName & customVariableValue.

Refactor API.getSegmentsMetadata and Plugin\Segment so segments are all defined through Plugin\Segment class in dimensions & make sure AutoSuggestAPITest data providers do not use database.

refs #5940 put tests in correct folders, better testsuite names, some tests still fail and I cannot figure out why

just noticed I broke the installer when I was trying to fix the updater in c01d57bc, this might work... basically the idea was ok but we should check for this only if the column actually already exists. If the column does not exist yet we need to make sure it will be installed

Fixes #4076  * Segment editor now displays for visitor IP the options "AT most / at least / great than / less than / equals / not equals"
 * updating doc to mention IP range filters
 * leaving Visitor IP in the Visit dimensions category in the segment editor (even though it's a "metric" by design). This is more clear this way.

Notes:
  - Added new visitId segment to get rid of getSingleVisitSummary API method.
  - Link to widgetized visitor profile in popup.
  - Added export link to visitor profile for visitor profile data.
  - Use CSS truncation instead of twig truncation in visitor log/last visits widget.

Creating getMinTimeProcessedForTemporaryArchive and splitting getMinTimeArchivedProcessed to make it clear.
Renaming class to Piwik_DataAccess_ArchiveSelector -- it will specialize in selecting archives