v3.1.7

Bugfix: Feature projection view
Correct y-axis values (PC2) are plotted when splitting on the diagonal
site pairs when PCA feature is selected.
Speed improvement: fft_clean operation (fft_thresh parameter) is performed faster.
New feature: Auto-splitting now supports manual splitting in three PC dimensions.
Auto-split now offers three choices: {'yes', 'no', 'manual'}.
Select "manual" and choose the projection ('PC1 vs PC2', 'PC3 vs PC2', 'PC1 vs PC3').