Plugin manager as modal window over GitExtensions

[maraf]

As suggested in #4 and #5, make PM a modal window.

[maraf]

How PM should behave when user has 2 instances of GE opened and starts PM from both?

[mast-eu]

How PM should behave when user has 2 instances of GE opened and starts PM from both?

We should avoid multiple PM instances which could install/update/remove plugins in concurrency.

IMHO a simple popup Another instance of PluginManager is already running would be perfect.
Can we achieve this?

[maraf]

IMHO a simple popup Another instance of PluginManager is already running would be perfect.
Can we achieve this?

Yes. We can even active / bring to front the already running instance.