0.4.1:
Updated documentation.

0.4.0:
Complete revamp of user interface.

0.3.2:
Allows differential and co-expression computation without input covariates (though not recommended).
Added UPDATES file.

0.3.1:
Allows to perform covariate normalization (in normcov) without adding constant 1 covariate. Useful for non-final covariate normalization.
Allows (but not recommended unless for very large datasets) to trade accuracy for speed in normalisr.association.inv_rank and its callers.
Added known issues in README.
Various minor improvments and bug corrections.
