made a start
added random generator to each particles, seeded on id. create_particles now serial
minor fixes
always use dirty_cells, keep track of celli for each particle
dirty_cells always used. embed_points_incremental added. compiles but need to test
embed_points_incremental fails due to inconsistant cells datastructure. but will merge since embed_points is ok
abandoning embed_points_incremental for now.....
added track ids, deep_copy for values, started adding some utils
rbf workes, but normalised to 27 rather than 1
minor fix
dirty cells not used after reset
merge with updating search