AssemblyDAO: Mark core as Installed.
AssemblyManager: Refactor code so UpdateAppDataFolder can be used internally to install addin.
AddinLoader: License information
AddinManager: Handle assembly update on StartAddin

On StartAddin, handle AssemblyUpdate/Install when it is not present
ou AppData folder, or when AppData folder is older than
DB version.
AddinManager: Install addin implementation
AddinManager: Unload Assembly after addin configuration.

In order to be able to update/start/shutdown addin during runtime, without
the need to restart the Addon, we need to not hold a reference to
the Assembly during runtime.

To do so, with this modification, the addin configuration is done in a
separate AppDomain, so we can unload it.
Form/Admin: Install addin implementation in form.
Form/Admin: Bug on start/shutdown/remove.

For those events, just implement if selected line is Addin.