Exclude vendor/ from ReleaseCheckList <?php test and remove setupProfilerXHProf that are no longer necessary.

Created unified system for running tests in travis for Piwik Core and any Piwik plugin. System includes a console command (generate:travis-yml) that generates a .travis.yml file for a plugin or core. The travis file will check in travis if it needs to be updated, and if so it will fail the build and tell the user. If a specific command line option is specified supplying a github user token, the .travis.yml file will be updated within travis automatically.

Notes:

  - comments and non-travis sections will be preserved
  - includes logic for plugins to test themselves against latest stable version instead of just on master
  - the system is primarily controlled by environment variables. developers can change/add variables in .travis.yml and the auto-updating will preserve the changes.

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

Add unit test check PHP files start with <?php -> prevent human error when IDE does not show white spaces

During tests, we shall load plugins that are in the .gitmodule file (official plugins found in marketplace),
as well as loading those that are in the global.ini.php (official plugins bundled in piwik).

refs #4373 fixes the merged assets file was only generate if it did not exist before and fix it also was not regenerated if a plugin was not updated. Therefore include the version number in the cache buster.

Adding release checklist test that fails if we add a new plugin or theme in plugins/* without specifying it in the Manager or the global.ini.php config. Adding the two themes that are bundled but were not set.