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

Refactor DbHelper::truncateAllTables() to truncate non-core tables, and tweaks to DatabaseTestCase tests.

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

Add new console command to setup fixture outside of a test so manual testing can be done w/ existing fixtures and so specific custom data can be added by creating a fixture. Includes slight refactor to Fixture.php.

- Rename *_BaseFixture to Fixture.
- Move DB setup code to Fixture and reuse code in DatabaseTestCase.
- Make IntegrationTestCase::$defaultApiNotToCall an instance var.

Refs #4202 removing functions Piwik_GetOption and SetOption. Now use: Option::get and Option::set and Option::delete

Added namespaces to functions.php files in the five plugins that had one
Work in progress

renaming Unzip to Uncompress,
Renaming Tracker/Referer to Tracker/Referrer,
and few more

Removed many Piwik_ functions, in Piwik 2 it is best practise to use the methods calls instead

Todo: finish converting core/ classes + convert plugins/ classes to use \Piwik\Plugin namespace + fix build + Merge master

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

Converting Access & Auth to namespace

2 steps required:

1. Refactor > Move > \Piwik\Core\Config (uncheck "Create new File")
2. Refactor > Rename > Piwik_Config to Config