[WCM] Embedded PHPCR Shell

Replaces existing commands with embedded PHPCR Shell.

Depends on: https://github.com/phpcr/phpcr-shell/pull/40

For example

````
$ php app/console phpcr node:list / # commands with arguments can be entered without quotes
$ php app/console phpcr "ls -L2" # commands with options must be quoted
$ php app/console phpcr node-type:list
$ php app/console phpcr "SELECT * FROM [nt:unstructured]" # queries must be quoted
````

good question.. I guess there are no good reasons that can't be cleaned up. Currently there is no stable release, and the dependencies are bleeding edge, but with the next round of releases this can be fixed.

A bigger concern is that it depends on both doctrine-dbal and jackrabbit. I guess we would have to have different builds / composer.json files, one for building the standalone and one for the embedded application (i.e. no transport deps).