Added used templates to Profiler

Based on a port of the Twig profiler which is part of
https://github.com/Elao/WebProfilerExtraBundle All credits to the
author of this package.
Delete TwigProfilerEngine.php
Manually merging #639: Added Twig profiling to debug bar

Thanks, @donottumbledry
Merge branch 'master' of github.com:bolt/bolt