language update  refs #3430
refs #5940 starting to rename test suites
Extend tracking with all changes.
moved some queries within core to model files

This is only a start. Especially the Tracker model contains quite a bunch of different models. Ideally, one day, the tracker is refactored and all the goal tracker stuff including the queries are in the goal plugins, all the ecommerce stuff is in an ecommerce plugin etc. Haven't moved some of the LogAggregator queries.
Ignore all errors in TestingEnvironment::logVariables()
Merge branch 'master' into 5940_testRenaming
refs #5940 IntegrationTestCase => SystemTestCase
refs #5940 databaseTestCase => integrationTestCase. Fixed some mentions of integration => system
refs #5940 fix tests do not run
refs #5940 fix customVariables tests
refs #5940 put tests in correct folders, better testsuite names, some tests still fail and I cannot figure out why
Merge pull request #6380 from czolnowski/extend-tracking-code-clean

Let plugins further extend tracking code via Event 'Piwik.getJavascriptCode'
refs #5940 splitting plugin tests folder into unit, integration and system for now
Remove token auth option from core:run-scheduled-tasks command since superuser access now allowed for all commands.
refs #5940 we might stay backwards compatible this way for 2 months. moved some tests from unit to integration and explained when a test is a unit test, an integration test or a system test.
refs #5940 there should not be a piwikDebugger plugin
refs #5940 fix hardcoded examplePlugin folder
refs #5940 fix namespaces
refs #5940 fix namespaces
refs #5940 this might fix the integration tests. Took me a long time to figure out what is going on. We should reset all the caches at least before each class otherwise the tests are no longer atomic and therefore worthless. This test was working when executing only this test but not when executing all tests