Planned API breaking changes - umbrella issue

[wprzytula]

Not to overlook any planned breaking API change scheduled for before we release 1.0, I group them here.

These are left for 2.0.

[roydahan]

@wprzytula please split this issue if needed for keeping the remaining list for 2.0.0, but with a list that is "sub-issue" vs "Tasks" which is deprecated feature.