Investigate impact of IOClass changes on changing profiles while buttons held etc

[evilC]

When making changes to IO handling, profiles lost the ability to release buttons when it went inactive .
This whole scenario needs to be investigated and a design settled upon.
In some cases (eg shift state support via profile inheritance), it may be desirable to not release held buttons when a profile goes inactive.

Note from previous ToDo: Plugin _OnInactive can no longer release held buttons