Rewrite "SITL on Windows native" topic to use new Windows 10 bash

[hamishwillee]

As it says in the heading. From lucas

• you have to install xming in order to see the windows
• it should also work to build for pixhawk

[davidbuzz]

The SITL/windows page in question is: https://github.com/ArduPilot/ardupilot_wiki/blob/master/dev/source/docs/sitl-native-on-windows.rst and is specifically written for windows 8 user/s. The windows10/Bash build environment is still experimental, but is found here: https://github.com/ArduPilot/ardupilot_wiki/blob/master/dev/source/docs/building-ardupilot-onwindows10.rst

I think the best thing to do here is leave the first/old page as-is, and highlight it's for Windows 8 ( and earlier), while creating a new "SITL on windows 10" page for it, as the process will be very different.( and is as yet not documented or even tested really. )

[auturgy]

Suggest closing this, as Bash in windows requires "workarounds" (aka hacks) to get graphical output, and the existing SITL via cygwin, and SITL with MissionPlanner, both function fine - so I don't see it as an issue per se. Of course if someone wants to contribute a guide, it would be welcome.