This test setup utilizes the "mocked" configuration so far only used for
manual testing. This allows adding unit tests for models without having to
run Syncthing itself. The test is pretty basic itself at this point.
* Add include directory for testhelper library manually as using the
imported target was not possibly
* Fix visibility when using libsyncthing in syncthingwidgets
* Update changed global headers along the way
Apparently this is still problematic leading to errors like
`Qualifying with unknown namespace/class`. It seems that moving the enum to
a different header file works. The trick to use a macro to define
`enum class` ceased to work on the other hand.
Specifying a function with the namespace like
`void QtGui::FinalWizardPage::showResults()` leads to the same problem and
also needs to be avoided.
Martchus