Code for dipole portal at DUNE

The source code is inside. ## Files - `main_DUNE.cpp` contains the main function, which calls `print_excl_curve<CLASS>(N_ threads, parameters..., EV, STEP_LEN, ...)`, which uses the predictor defined by `CLASS`, to find the `EV` events/year curve in parameter space starting at `parameters...`and using length `STEP_LEN`. For the pure dipole case, the mass-mixing parameter `Usq` is normally set to zero.

Note that the program automatically uses `N_threads` threads, whose default value is 4. Use `run.sh` to use the correct number of processors. - In `pred_in_out_DUNE.hpp`, a wrapper class is defined, which contains both the inside- and outside-events predictor. - The files `predictor_DUNE.*` contain the class for the outside-events predictor. This class inherits from `predictor_base.hpp`, which deals with the precomputation and tabulation of the kinematic factors in the integrand, like the cross section and anything depending only on the momenta and scattering angle of the incoming and outgoing neutrino.