New solveRLM with sparse keyword

* new does not support conditional
* old renamed to solveRLM_conditional (used in init)
 * old only supports one point type
 * solveRLM_sparse can be deleted, new performs better
 * 0.875540 seconds (5.11 M allocations: 543.265 MiB, 9.95% gc time)

Author: Affie