Add touch support for pointer based devices

[DanielX2]

Add touch support for pointer based devices like ie11 on Windows 8.1.

I tested these changes with following devices and browser:

• Surface Pro with ie10(win8.0) and ie11(win.81)
• Ipad Safari (IOS7)
• Desktop with ie10, latest Chrome, latest opera, latest Firefox

At the moment I can't build the source file out of the repository, because I dont know the build process. (this is my first github Action)

[mourner]

You need to fix the whitespace so that I could see the diffs correctly (Leaflet uses hard tabs, not spaces).

Also, it seems that you wrote a new implementation of pointer events despite that we already have one here https://github.com/Leaflet/Leaflet/blob/master/src/dom/DomEvent.MsTouch.js — was there a particular reason?

Thanks!

[mourner]

Also, you can read how to set up the build process (and correspondingly fix the build errors) here: https://github.com/Leaflet/Leaflet/blob/master/CONTRIBUTING.md

[DanielX2]

Sorry, i didn't see that my diffs are going trough the hole files, i will fix this and update it.

I thougth it would be better to implement a new handling, because i don't know if now and in future msPointer and pointer are working the same way.

Currently it seems as they would, but im not sure if they would do so if you want to implement new features. So i decided to do a new implementation.

But i could implement the pointer handling in the msPointer handling, if you want me to do this?

PS: Thanks for the link to the build process.

best regards

DanielX2

[mourner]

Closing in favor of #2066