The frist release of the cplxmodule library.

Merge branch 'pre-release' into master for the first 2020.03 release

specify .nn.utils in setup

tagging to fix the version

Tagging before directory structure revamping of the module

Tag on the 10th of December, 2019, before implementing new stuff

Tagged for legacy support an hour past midnight on the 22nd of Novemb…

…er 2019,

Tagged in the 15th of July, 2019, before merging branch 'experimental…

…' into master.

Tagged on Tuesday, the 25th of June, 2019. This verson seems to be re…

…ady for general use.

Masking layer are properly serializable and de-serializable. The new sparsity statistics
protocol seems to be working (judging by possible upcoming tt-layer PR) and extensible.
Real and complex relevance detection was compactified, refactored a bit and sped up.

Tagged on th 18th of June, 2019, after completely redesigning the bug…

…gy sparse mode.