FIX july
FIX copying index, considering _parent field if one is set.
IMP introduce a utils.sh library shared between script to
    stop duplicating code.
ADD migration script to introduce the site name of every ad.
ADD first version of ad expiration detection batch.
To implement: expiration detection for every site
IMP access index through alias instead of index versionned name.
ADD prepare for ads expiration detection batch.
    all site helpers ready.
ADD expire_pubs.py mark expired ads as such.
ADD do not examine already expired ads for expiration.
CHG use alias instead of versioned index name.
ADD display expired ads with a dedicated css class.
ADD purge expired and not likes ads.
Merge branch 'master' of github.com:pgrange/risno