remove IDE / OS specific ignore rules

These have nothing to do in a repository, they should be ignored
globally. What if everyone does the same with their custom IDE / OS ?
choose route builder depending on the manager type

sonata.admin.route.path_info_slashes is a more sensible default if you
use PHPCR, because since Document ids can contain slashes, the regex
that capture it must be able to tolerate these slashes, which is the
main goal of this route builder.
Merge pull request #2215 from greg0ire/choose_route_builder_wisely

Choose route builder wisely