travis.sh will now check that all tests have been tagged with @group comment. THis will help us detect when new tests are added which wouldn't otherwise be executed by travis

Enabling All plugins during tests

Deleting Plugin\Config since it wouldnt be best practise to have per-plugin config file. Waiting for refs #4126

fix "Fatal error: Cannot use Piwik\Config as Config because the name is already in use" when generating documentation

fix "Fatal error: Cannot use Piwik\Config as Config because the name is already in use" when generating documentation

fix "Fatal error: Cannot use Piwik\Config as Config because the name is already in use" when generating documentation

Fix several bugs/regressions in site selector including double encoding when search result is clicked, down arrow overlap w/ loading icon, and dropdown changing size after selecting a site w/ a long name.

Viewdata cleanup

Visualization cleanup

added interface for dataTable to be able to define the expected type in a function, maybe it makes sense to add/remove some methods from the interface?