Update changelog for 1.7.3
Merge branch '1.7' into 1.8

Conflicts:
	docs/changelog.rst
Add 1.8.3 to changelog
Merge branch '1.8'

Conflicts:
	docs/changelog.rst
Update Releases requirement for needed bugfixes
Merge branch '1.7' into 1.8
Merge branch '1.8'
Modified changelog w/o releasing...
Merge branch '1.7' into 1.8

Conflicts:
	docs/changelog.rst
Merge branch '1.8'