Merging Clints repository to yours

Well having the cutscenes and some refactoring at the mainline repository, will cause some merge conflicts for the minions. As I did most of the refactoring and I don't want to bring the merge conflicts as your burden, I resolved these merge conflicts. Feel free to resolve them yourself, or taking this version.
This pull request is basically the same as https://github.com/clintbellanger/flare-engine/pull/550 However the cutscenes and the refactoring have been integrated into Clints repo with https://github.com/clintbellanger/flare-engine/pull/545

This PR contains a few commits, which are not yet part of the mainline repo:

f632f70 Files including Utils, do not need to include SDL on their own
56bca25 Initialize variables in constructors.
bce3150 Remove unneeded Entity::face
b5368ef Merge minions into cutscenes_and_refactoring_and_minions
04e8ebe Replace whitespaces by tabs.