Require julia 0.3 or later.
Truncated constructor expects Float64 arguments instead of Real.
Truncated minimum and maximum now included in Distributions package.
unwhiten_winv and unwhiten_winv! removed from PDMat package.
Change StridedVecOrMat to DenseVecOrMat.
Remove currently unneeded version bounds.
Update documentation version to 0.3.8.