Fix implicit buildmode documentation and adjust test accordingly

This basically turns the issue #21 into a feature by correctly describing the constraints of the implicit build mode and the meaning of its parameters. This invalidates the test against the old interface description which is hence dropped by this MR. As a consequence the bcrsimplicitbuild-test passes again.

Mentioned in issue #21

Reassigned to @carsten.graeser

Reassigned to @dominic

@dominic: Please check if the documentation is correct now and merge afterwards to get the CI green again.

Reassigned to @carsten.graeser

Since this surely improves the docs I'll merge on my own in order to render the CI more useful again. @dominic: Feel free to improve the documentation afterwards if this is not enough or misleading.

Mentioned in commit 47fc9a57

Status changed to merged

Mentioned in commit 63e7bfa2

Mentioned in commit 976cbd8d

Mentioned in merge request !67 (merged)

Mentioned in commit 4db1e389