Add identifiers for slot and projects
The idea is that any slot or project built in the nightly builds can be identified by a string.
For example, nightly/lhcb-gaudi-head/1234/Rec identifies the project Rec in the build 1234 of the slot lhcb-gaudi-head (nightly refers to he CouchDB database hosting the details).
This kind of ids can be used to retrieve the project or slot details from CouchDB.
Edited by Marco Clemencic