Memory leak due to event handler

[ghost]

Here's a memory leak: https://github.com/modern-forms/Modern.Forms/blob/51f917aea77b2ae4fe88eadd18988fb3633402fd/src/Modern.Forms/Control.cs#L53

[jpobst]

Nice catch! I'll have to give some thought to how I want to fix this.

[jzlhll]

Sound like singleInstance add handler once again. Maybe should remove it before add or only add once.