SoftResetHandler can not be disabled

[davidenke]

What is the problem

Using a hard reset for changed main file makes sense, but it always registers a soft reset handler as well.
If already some development server is used (or some hmr magic) it would make sense to opt out from the soft reload handler registration as well.

How to reproduce

Use e.g. Stencil in conjunction with Electron.

Additional information

This should not be very difficult, just introducing a new option and a condition for the handler registration.
I would provide a PR if wanted 😀.