add "disableaddmarker"; fix popped+clickable+ heat

[PizzaProgram]

fixed:

- heatmap error
- popup inconsistencies
- popped
- clickable
- speed optimisations

The only tiny problem with it, is still:

- if popped from code, but popup is closed with the X at the corner, than msg.payload.popup is showing the wrong state
- So the user has to click 2x the next time, to force-show popup again.

Whole conversation here:
https://discourse.nodered.org/t/wordmap-marker-popup-open-visible/100734/12?u=pizzaprogram

[PizzaProgram]

Also Added a new command:

• To be able to disable right-click "Add marker" context menu: {"command":{"disableaddmarker":true}} (default false) Similar to hiderightclick, but this command still allows marker's context menus.

[dceejay]

Hi - as per original discussion I would prefer separate Pull Requests for different issues - as I believe I have already address both the heat map and popped, popup issues in the master branch already, and need to review/understand the extra commands as I'm not convinced we need both of them now you know the popped state etc. - so I won't merge this one as-is, but will look at it to try to work out what's going on.

[dceejay]

Thinking about it - you can already disable the right click add marker item context menu by sending a generic command

msg.payload = { 
    command : { contextmenu: "" }
}

This is at the map level rather than individual marker context menu level.