Actually it depends on the contract you signed before you start working for any company in Doha. Each company has different policies whether they are government or private.For companies like QP, Rasgas,Qatargas, they are offering three weeks of your monthly salary calculated for each year.Ticket and other are depending also on the clause on your contract. If you are locally hired and it doesn't say in your contract that you will be given plane ticket, then that one is not included. Also, in some companies are shouldering the cost of cargo freight to send your things (i.e. home furnishing, appliances) back to your home country.
I hope this info helps.