added a simple test to make sure we do not break the external widgets API and keep the same URL renderable

That avoids any change for people integrating the widget in their websites, and hopefully that should reduce a lot of the UI screenshot differences.

In general it makes no sense to do this, and it could have security implications to allow it.

fixes https://github.com/piwik/piwik/issues/7184

Fixes #3147 Add rel="noreferrer" to all outgoing links . This works in Firefox so far and only for "left clicks". Not perfect, but hopefully other browsers will implement this in the future, as it's a useful privacy enhancing feature!

Moved IE conditional statements to body to prevent ignoring the X-UA-Compatible tag by IE

refs #6140 easier way to define URLs for menu items and introducing a method to addItem without boolean parameter

refs #5863 another try to move translations into plugins. This time we always load all translations of all plugins that are not 3rd party and bogus. As the translation file will be cached the time to load the translation drops from > 10ms to 1ms

refs #5192 some more menu api tweaks. MenuReporting is not 100% good since it is in core and should not know whether are actions, referrers and visitors item but it is very convenient for developers. Once we have DI we could add those methods there

This reverts commit 62ba8dfb.

refs #5326 as mentioned in the ticket once we have simplified the reports we can simplify the widgets api even more which is done in this commit, it might be not perfect yet but again much better than before

make sure to display a message "you do not have permission for this site" if needed before displaying any information whether a report exists or whether a report is enabled... In theory someone can find out whether a certain report is installed but this was already the case before.

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

refs #5222 the defaults theme javascript files are not added by a plugin.json definition, we have to add them separately

removed zeitgeist theme, morpheus is standard theme now, still need to remove duplicated / deprecated stylesheet definitions