RPM Support

The reason is that Pulp stores filelist in the parsed form in db, with #723 there is more room for it then before (it was ~5-6MB at most), but still it is limited.

Here is a parsed filelist of rpm unit from `units_rpm` collection:

    "files" : {
        "file" : [
            "/tmp/camel.txt"
        ],
        "dir" : [ ]
    }

I do not have any statistics on how many such repositories are there in the wild, so far we know at least one oVirt repo:
http://resources.ovirt.org/pub/ovirt-4.0/rpm/el7/

The RPM which causes troubles is `ovirt-engine-nodejs-modules`, version 0.0.8.

<package pkgid="dd58f5a72e38ebd6c1ef2ed2426276ae1255a7f8727cb6911b733a2820df9237" name="ovirt-engine-nodejs-modules" arch="x86_64">
  <version epoch="0" ver="0.0.8" rel="1.el7"/>