'Live' fields stop responding when forms are undocked

[jeroens]

Input fields in the EwE user interface are connected to underlying data using Format Providers, which ensure standardized formatting, colour feedback, and live data changes.

The docking framework in EwE allows forms to be torn out of the EwE user interface. This underneath destroys and recreates the Windows controls wrapped by .NET. This trigger was sufficient to detach the controls from their format wrappers, thus breaking their ability to follow live data changes, and to submit data changes to the core.

[jeroens]

Changed event handler in EwEFormatProvider: no longer auto-release on Control.HandleDestroyed?, but on Control.Disposed. Note that disposal will not occur if the providers keep a hold on the handle of controls, but this is the best I can logically do.