Generalized-norm conjugate direction solver

Summary

We have provided this implementation of the generalized norm solver to SEP for benchmarking and testing on a variety of sample problems. These experiments have been documented in separate SEP reports which focuses on the geophysical ramifications of the $L_1$ and modified $L_1$ optimization criteria. In conclusion, our solver has been designed to be interchangeable with existing codes, requiring minimal code modification. We hope this will encourage other researchers inside and outside SEP to experiment with these available optimization objectives.