[Development] Switch the main "Qt Build System"

[Alexandru Croitor]

> On 10. Jun 2020, at 03:35, Lorn Potter <lorn.potter at gmail.com> wrote:
> 
> 
> 
> On 9/6/20 11:23 PM, Alexandru Croitor wrote:
>>> - WebAssembly completely lost
>> That is true. As I mentioned in my reply to Andre, we tested it at some point, but we don't have current plans to add it to the CI.
> 
> I would be surprised if it actually built, as emscripten compiler for Qt WebAssembly needs special linker flags (beyond what is in the toolchain file), as well as in the platform app build, we move files and sed replace strings to make it all work.
> 
> I spent an hour or so today trying to get dev branch built for webassembly using cmake, and could not get past the initial cmake call.
> 

Note that my "tested at some point" did not mean it works now. Merely that a conclusion was made that it should be doable. 

Personally I never dove into gritty details of making it work, and when I tried to set it up once, I failed as well.

But I know that when somebody did look into it, they were able to build qtbase (this is when we were still using vcpkg for some of the 3rd party dependencies).