cmake: add build_tests target

I added a new custom target 'build_tests' that has all test executables
as dependency. In development versions build_tests is made with all, in
release versions you'll have to make build_tests explicitly. A standard
make all will then only build libVc.

Signed-off-by: Matthias Kretz <kretz@kde.org>
docs: don't generate LaTeX and man

The latex output from doxygen is broken (missing namespaces.tex) and the
man output looks too unreadable to be useful. So I'd rather only keep
the HTML variant for now. Until somebody wants to maintain one of these
other outputs.

Signed-off-by: Matthias Kretz <kretz@kde.org>
release script: no tests & build docs

* remove build_tests from all target for release tarballs
* run doxygen and store qch file and docs tarball

Signed-off-by: Matthias Kretz <kretz@kde.org>
release script: bail out if tagging fails

Signed-off-by: Matthias Kretz <kretz@kde.org>
docs: remove .qhp file when done

The .qhp file is an intermediate file that can be removed after the .qch
file is created.

Signed-off-by: Matthias Kretz <kretz@kde.org>
macros: fix __OPTIMIZE__ ifdef

The logic needs to check for defined() not just the value of
__OPTIMIZE__.

refs #655

Signed-off-by: Matthias Kretz <kretz@kde.org>