First try at modeling cms parts

Test with following code

	<?php
	require_once('base/lib/inc.php');

	$p = SystemPart::getPart('plugins/redirect');
	$p->resolveDependencies();
	var_dump(SystemPart::getPart('base'));
Successfully detect System part ordering
Test implied orderings
add a test info.yml w/ version info
No version info necessary
Use SystemPart when determining plugin order

in ResourceFinder
Merge branch 'topological-plugin-sorting' of git://github.com/rapila/cms-base into topological-plugin-sorting

* 'topological-plugin-sorting' of git://github.com/rapila/cms-base:
  No version info necessary
Merge branch 'topological-plugin-sorting'

* topological-plugin-sorting:
  Use SystemPart when determining plugin order
  No version info necessary
  add a test info.yml w/ version info
  Test implied orderings
  Successfully detect System part ordering
  First try at modeling cms parts