avoid name clash with phpcr-utils in composer

phpcr-utils provides a bin/phpcr file and composer wants to symlink files in bin in the project bin file, leading to 

    Skipped installation of bin/phpcr for package doctrine/phpcr-odm: name conflicts with an existing file
    Skipped installation of bin/phpcr.php for package doctrine/phpcr-odm: name conflicts with an existing file

in the case of symfony projects, those bin are pointless as the phpcr-bundle exposes all the commands to the symfony console.
@Seldaek is there a way to tell composer not to include a bin if we are in a symfony project? ideally from the included repository, not as a project wide setting...