Modfied __getitem__ method of Vector valued modular forms.
Added a method _none_zero_tpl for SymmetricWeightGenericElement.
SymmetricWeightModularFormElement inherits HeckeModuleElement.
Fixed _from_dict_to_object of SymmetricWeightGenericElement
and SymmetricWeightModularFormElement.
Added some functions for the Hecke action on vector valued
modular forms.
Implemented __hash__ in HalfIntegralMatrices2.
Added an attribute _is_scalar_valued.
Modified SymmetricTensorRepElement.
Moved _is_triple_of_integers to utils.py
Refactoring.
Added class SymTensorRepElt.
Added method _hecke_op_vector_vld.
Modified euler_factor_of_spinor_l and
euler_factor_of_standard_l for vector valued modular forms.
Moved SymTensorRepElt to hecke_module. Implement method zero.
Added a test for T(2) action on a vector valued modular form.