Merge simplified euler to optic flow

.coveragerc

.gitlab-ci.yml

CHANGELOG

CONTRIBUTING.md

LICENSE

README.md

doc/source/conf.py

doc/source/gettingstarted.rst

doc/source/index.rst

doc/source/media/marked_bumblebee.png

doc/source/overview/database.rst

doc/source/overview/examples/blenddemo_beesampling.py

doc/source/overview/moving.rst

doc/source/overview/rendering.rst

doc/source/references/index.rst

doc/source/references/maths.rst

doc/source/references/processing.rst

doc/source/tests/brain.rst

doc/source/tests/comparing.rst

doc/source/tests/database.rst