Use `--check-library` for all tests as it was done before.
Re-enable all tests in runtests.sh again.
The regressions where runtests.sh would fail are disabled via "FIXME"
comment in the inline suppression comment.
To be able to use real Qt-Code in "test/cfg/qt.cpp" and still do a
syntax check the Qt settings are read out via pkg-config now if it is
available. This way the test now can contain Qt macros and functions and
the syntax check can still be used.
Additionally the same options as for the other tests are used now for
the Qt config tests.
Installing the package "qtbase5-dev" should be enough to enable the
syntax checks (already installed for travis tests).
Sebastian
Daniel Marjamäki