Photoassociation of cold calcium atoms through the A^{1}Σ_{u}^{+}(1^{1}D+1^{1}S),c^{3}Π_{u}(1^{3}P+1^{1}S), and a^{3}Σ_{u}^{+}(1^{3}P+1^{1}S) states: An ab initio nonadiabatic treatment