Add Laravel 5.8 support (barryvdh#911)

In case of insert/update/delete query, do not explain barryvdh#888 (b…

…arryvdh#903)

*workaround*

\Exception isn't well with newer PHP (barryvdh#886)

Fix for policies (barryvdh#860)

Policies cannot be used now due to this reason. And additionally, the method `Auth::user()` returns the class `Authenticatable` (which is used in gates), not `Authorizable`.

Also, I believe the class `Authenticatable` should be used since it is checking its instance on the line 33.

Fix no queries being collected anymore (barryvdh#827)

Missing negation

If user is instance of Authenticatable call getAuthIdentifier() defin…

…ed by the interface rather than assuming it has a public id field (barryvdh#799)

Add SimpleFormatter for faster exporting

Replaced use of removed ValueCollector with VarCloner (barryvdh#787)

* Replaced use of removed ValueCollector with VarCloner

As per L5.6, Symfony 4 is now used.  As such, VarCloner must be used in place of ValueCollector.

* Changed PHPDoc for exporter.

Allow to use nullable user (barryvdh#786)

Update debugbar.php