Added whitelistedMouseEvent option

[fildahui]

Whitelisted mouse events

This change introduces a new option, whitelistedMouseEvents, that lets users specify an optional list (array) of events whose execution will not be stopped.

The problem, that made this change necessary, was occurring in an ionic application, with snazzy info window template configured to not display the close button.

After opening the first snazzy-info-window it would remain open forever even when tapping on a different area of the map. This was because all the mouse/touch events were being stopped.

Now users can set the proper option (whitelistedMouseEvents) using an array of events, preventing all of them from being stopped.

[devonmather]

This is a great addition 👌🏻

[SrgSteak]

Why is this PR still open? I really need this in a project I'm working on