New example ode_spline. NcClusterRedshift transformed in NcmModel.

Transformed all NcClusterRedshift and descendants to NcmModel.
Fixed nc_hicosmo_de prototypes for better bindings. New get/set functions by parameter names.
Organized mc samplers in NcmMCSampler abstract object. New methods for Vector, Matrix, Model and MSet. Fixed bugs in NcClusterPhotozGaussGlobal.
Fixed wrong casting.