weird 2.1.0

• Added surprisals() and surprisals_prob() for glm objects
• Faster calculation of surprisals_prob() for lm and gam objects
• More accurate rank-based surprisal calculation when ties and missings present
• More accurate HDR calculations
• Added covariance calculation for multivariate dist_kde objects
• Added distributional::hdr() and distributional::parameters() methods for dist_kde objects
• Faster calculation for kde_bandwidth() with method = "lookout", now using mlpack for merge distances
• mvscale() re-added to weird
• Dropped lookout package dependency
• Added lots of unit tests
• Better docs
• Bug fixes