Custom dispatch function (#75)

* Allow passing a function to use for dispatching events

* Add doc for new param

* Fix tests

* Update package-lock.json

* Separate dispatch functions better

* Also allow custom message authorization functions

* Move beforeunload handler

Co-authored-by: Jamie Countryman <[email protected]>

Author: jmcountryman

.nvmrc

@@ -1 +1 @@
-10.6.0
+lts/dubnium