Revised the way how multiprocessing is called in the 3D transformer (replaced...

Revised the way how multiprocessing is called in the 3D transformer (replaced with pool.imap_unordered without initializer). This is as fast as before but has a much smaller memory consumption enabling the algorithm to also run on smaller machines while still highly benefiting from more CPUs. Fixes issue #5. Updated HISTORY.rst.

Signed-off-by: Daniel Scheffler <danschef@gfz-potsdam.de>
2 jobs for enhancement/reduce_memory_consumption in 1 minute and 41 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
passed test_sensormapgeo #35775

00:01:25

88.0%
passed test_styles #35776

00:00:16