This package is a very minimal subset of the external library `controlsfx`.

Three files were embedded into the project to avoid having `controlsfx` as dependency.

This is based on version `8.0.6_20` tagged in commit 6a52afec3ef16094cda281abc80b4daa3d3bf1fd:

[https://github.com/controlsfx/controlsfx/commit/6a52afec3ef16094cda281abc80b4daa3d3bf1fd]

These specific files got raw copied (with package name adjustment):

[https://github.com/controlsfx/controlsfx/blob/6a52afec3ef16094cda281abc80b4daa3d3bf1fd/controlsfx/src/main/java/org/controlsfx/control/PopOver.java]
[https://github.com/controlsfx/controlsfx/blob/6a52afec3ef16094cda281abc80b4daa3d3bf1fd/controlsfx/src/main/java/impl/org/controlsfx/skin/PopOverSkin.java]
[https://github.com/controlsfx/controlsfx/blob/6a52afec3ef16094cda281abc80b4daa3d3bf1fd/controlsfx/src/main/resources/org/controlsfx/control/popover.css]
