Make conflicts events more informative.

Write information about package origins for both packages from the
conflict pair. Now the json variant looks like this:
{
    "type": "INFO_INTEGRITYCHECK_CONFLICT",
    "data": {
        "pkgname": "memcached",
        "pkgversion": "1.2.8_3",
        "pkgorigin": "databases/memcached12",
        "pkgpath": "/usr/local/bin/memcached",
        "conflicts": [
            {
                "name": "memcached",
                "version": "1.4.15",
                "origin": "databases/memcached"
            }
        ]
    }
}

Suggested by:	bapt