Add option to write jumps as event list in CSV format.

$ cargo run --release -- /mnt/c/Users/reichold/Documents/swifcoibm/install/test/asf_release_pol.csv --cell-size 4000 --fields x y day --jumps /dev/stdout
   Compiling grid-spread v0.1.0 (/home/adam/grid-spread)
    Finished release [optimized] target(s) in 9.82s
     Running `target/release/grid-spread /mnt/c/Users/reichold/Documents/swifcoibm/install/test/asf_release_pol.csv --cell-size 4000 --fields x y day --jumps /dev/stdout`
x, y, day
473026.3321001751, 5828745.932105737, 658
474830.2535758822, 5817396.373730007, 675
506889.9087272943, 5797933.016093433, 678
520971.4075964409, 5789321.540213743, 675
510246.3191492189, 5785858.209058005, 667
482281.16400717024, 5781553.770281792, 646
544724.9925439432, 5781631.050944947, 643
494471.5406162132, 5779702.306459407, 678
534040.3288622597, 5777684.0546218455, 636
501997.3443954855, 5773458.6536491355, 667
525177.8904330104, 5774974.081803931, 598
542566.1800948555, 5776452.086559362, 511
509496.2109875007, 5771273.629100687, 643
535978.7497095265, 5772476.146808862, 510
491010.25105816097, 5767194.529338364, 643
497638.00669355714, 5766538.097934657, 650
561826.5916642299, 5765747.025870145, 441
508769.7469439181, 5762343.557826457, 598
509323.5066757896, 5761850.174138857, 598
518207.96905611595, 5762029.172717034, 584
527975.9274636848, 5764360.738149379, 598
562283.1588699308, 5762755.4212393, 441
535087.9498761698, 5758442.705610486, 678
544183.5241050315, 5759132.748790503, 517
517599.6610149109, 5756095.100963455, 654
574003.3715228688, 5754170.663853714, 475
524846.247622957, 5745992.192767133, 664
529939.7501794223, 5748275.292125903, 678
579073.2496638293, 5746399.4568756735, 496
513163.0259184203, 5744619.394257414, 678
495516.69958580466, 5737498.430132773, 628
531761.1691652412, 5738400.076746653, 678
558770.4197491156, 5738704.966140458, 513
568364.9888266397, 5737590.336923103, 471
505503.1568525649, 5733452.309549818, 383
585754.4738968546, 5736064.506912435, 510
518934.0246542127, 5731229.703306344, 664
526624.2617195989, 5731696.998056752, 507
552072.9890673514, 5730536.1939758295, 678
535564.5843003619, 5728786.207873009, 667
574103.6470857204, 5727876.488407191, 682
522045.79016101727, 5721510.723979782, 415
500845.81755071186, 5720659.414464263, 664
511382.00116754364, 5719899.866620935, 510
561035.8167220264, 5720873.315340415, 626
529690.1930602712, 5715896.146345089, 664
489837.9378374626, 5705037.734661351, 661
507266.4326275067, 5707257.042644136, 664

Fixes #1 (closed)