Integrate the logging framework

Let's bring in the PSR-3 logging framework as well as the idea of D8 to have dedicated logger channels.

Note: We can't use the generic code of d8 at least for now because we neither have RequestStack nor AccountInterface at the moment.
Technically though we could both implement probably, let's do that though first in other PRs
parent is not implement by the current container, also traits are not supported (due to wanting to support PHP 5.3), can we make LoggerChannelFactory ContainerAware and use setContainer in calls instead?