Add changes for 0.19.0 to the CHANGELOG

The items are based upon the commits between 0.18.1 and 0.19.0 that were no
related to things like consistencies in the code (using double quotes for
example), docs, and specs.
Add changes for 0.19.1 to the CHANGELOG

Based on the handful of commits between 0.19.0 and 0.19.1, add what was fixed in
0.19.1 to the CHANGELOG.
Merge pull request #449 from thoughtfaucet/bmc/changelog-0.19.0-and-0.19.1

Add CHANGELOG changes for 0.19.0 and 0.19.1