A workaround for SONARPLUGINS-2303 and a problem with traits support in PHP Depend.

* PHP Depend doesn't generate any metrics yet for classes using traits
* Because of Issue #111 (https://github.com/pdepend/pdepend/issues/111) in certain circumstances
  it adds a method node to package node outside of a class node - defined a list MethodsNode on a PackageNode
  so Sonar can at least successfully parse the summary report.