Update CHANGELOG with recent changes

A few of the previous commits forgot to include changes to the
CHANGELOG. Add them now for history's sake.

Change-Id: I1df00323acb67f77910b9b759e2b7faaceebe6b0
Reviewed-on: https://gerrit.causes.com/28949
Tested-by: jenkins <jenkins@causes.com>
Reviewed-by: Shane da Silva <shane@causes.com>
Upgrade Sass gem dependency to 3.2.10

Includes the following fixes to the Sass parser:

 * Preserve the `!` in `/*! ... */`-style comments.

 * Fix a bug where selectors were being incorrectly trimmed when using
   `@extend`.

Change-Id: I7b38ea7eae03b936810d9f7d6e6867982d929d30
Reviewed-on: https://gerrit.causes.com/28950
Tested-by: jenkins <jenkins@causes.com>
Reviewed-by: Shane da Silva <shane@causes.com>