[REQUEST] Improve heatmap loading.

[Coalado]

Checklist

• [X ] I have read the FAQ
• [X ] I have checked if this issue already exists (both open and closed issues)
• [X ] I am using the most recent version of pogom from the master branch
• [X ] If this is an installation issue, I am posting my OS, OS version, python version, pip version
• [ ] I'm posting the complete log
• [ X] I'm using a descriptive title for this issue

  My Issue

The heatmap can become pretty big. It's already a few MB in my case. It would be good to load it only when required. Example:

• only for pokemons in the heatmap list.
• only for the current viewport

...

[nborrmann]

Protip: Setup an actual webserver (nginx) in front of flask and let the webserver gzip all responses.

[Coalado]

Good idea.

[Koire]

Yeah, sorry about that, I only made a working heat map. To do it quickly, I made it generate all the heat maps, then allow you to choose which one you want. To do what you want, you have to reverse the current function to generate a heat map when you add a mon to the heat map list. (if you notice, the heat maps don't do well layering on top of each other, but that's an easy fix)

Edit: I'll fix it.

Second Edit: @nborrmann Does it make sense to be able to select multiple pokemon? It will end up strengthening the areas with overlapping mons, but you won't really be able to tell what mon goes where. It is possible to give a heatmap a palette, but, I don't think that helps visualising.