Updated CHANGES for 0.4.0 release.
Updated CHANGES for 0.4.0 release.

This is likely not complete (> 1000 commits since 0.3.0... fail!),
but hits many of the major things.

nicholasmalaya/grins,cahaynes/grins,vikramvgarg/grins,vikramvgarg/grins,cahaynes/grins,vikramvgarg/grins,vikramvgarg/grins,cahaynes/grins,cahaynes/grins,nicholasmalaya/grins,cahaynes/grins,nicholasmalaya/grins,vikramvgarg/grins,nicholasmalaya/grins,cahaynes/grins,vikramvgarg/grins