The much-heralded children’s library project slated for the downtown library got a $1.7 million shot in the arm from the City Council to help underwrite the construction effort — plus the creation of an endowment — slated to be $5.6 million. Most of the money will be spent on refurbishing the downstairs of the Central Public Library to make it a service-rich kid magnet. Plans and fundraising efforts for this endeavor have been kicking around for more than 10 years, but with the receding of the recession, they’ve taken on a new life.