Implement posterior_mode and fit_map for a series of distributions.
Change parameterization of InverseGamma (using the wikipedia way)
Added Normal-inverse-{gamma/Wishart}.
posterior_sample returns a Distribution with params sampled from posterior.
Added posterior_sample specialization for univariate Normal.
Added MvNormalSuffStats to store sufficient statistics for MVN.
Posterior computations for Normal-inverse-Wishart.
Handle Gamma prior on precision in conjugates.jl.
Placeholders for normalgamma.jl, normalnonconj.jl, and normalwishart.jl.
NormalInverseGamma uses variance param.
Implemented basic NormalGamma.
Moved multidimensional log-gamma function to specialfuns.jl.
Renamed matrix parameter to match Murphy and fixed logpdf.
Added Normal-Wishart distribution.
Moved conjugate Normal stuff to conjugate-normal/.
Added placeholders for tests.
Tests for MvNormalStats.
Fixed weighted outer products for MvNormalStat test.
Fixes some bugs in normal conjugate distributions.
Moved non-conjugate placeholder to normalsemiconjugate.jl.