[sources management] nicer source management view and breadcrumbs (closes #1946329)
* nice 'add host config button'
* table displaying host configuration
* display a source's config using <pre> or something like that that respects EOL
* configure breadcrumbs for CWSourceSchemaConfig and CWSourceHostConfig
#! /bin/sh -e#if [ "$1" = configure ]; then if which install-docs >/dev/null 2>&1; then install-docs -i /usr/share/doc-base/cubicweb-doc fifi#DEBHELPER#exit 0