[POC} Added iterations and dataprovider

This is a quick and dirty PR that:

- implements data providers 
- allows multiple iteration speciications 
- forces to prefix the method with `perform`.

If it is interesting I could break it up into separate PRs and write it properly...

For example:

````php
    public function provideFullTreeTraversal()
    {
        return array(
            array(10, 100),
            array(20, 200),
        );
    }

    /**
     * @dataProvider provideFullTreeTraversal
     * @iterations 1
     * @iterations 10
     */
    public function performFullTreeTraversal($from, $to)
    {
        $rootNode = $this->getSession()->getRootNode();
        $this->iterateNode($rootNode);
    }
````

Produces:

````
PHPCR\Benchmark\Suites\Reading\TraversalEvent
    Method Name                        Iterations   Average Time     Ops/second
    ---------------------------------  ------------ ---------------- -------------
    FullTreeTraversal(from=10,to=100): [1         ] [0.0515341758728] [19.40460]
    FullTreeTraversal(from=10,to=100): [10        ] [0.0038705348969] [258.36222]
    FullTreeTraversal(from=20,to=200): [1         ] [0.0037219524384] [268.67619]
    FullTreeTraversal(from=20,to=200): [10        ] [0.0038553476334] [259.37998]
````