[QBS] what about path magic variable?

[Smirnov Vladimir]

> Vladimir, you can use
>
> Export {
>      ...
>      cpp.includePaths: ["."]
> }
>
> as a temporary workaround.
I already widely use Export item, I didn't know that such use IS 
"workaround" (just thought it's normal).

> It's not documented because it is a terrible name that needs to change.
> Seehttps://bugreports.qt.io/browse/QBS-246.

Ah, I saw that bug, but didn't linked it with.

In conclusion, if this var is undocumented and will changed, maybe we 
shouldn't use it in examples?