Merge pull request fzaninotto#1865 from pimjansen/release/1.9.1

Added changelog for the 1.9.1 release

Bump version to 1.9

Update changelog for 1.8.0

Bump version

Prepare Release 1.7

Tagging 1.6.0

Merge pull request fzaninotto#585 from fzaninotto/prepare_1_5

Prepare 1.5 release

Releasing v1.4.0

Fix composer version

Update composer branch alias