Use CMake FeatureSummary
Use the system Qt5 includes instead of a fake definition
Fix line numbers in test output
Add ClangUtils::getLeastQualifiedName()

This moves the code from ConnectCallMatcher::calculateReplacementStr()
to a new function so it can be reused by convertDisconnect()
Fix ClangUtils::isNullPointerConstant returning the wrong value

The if statement was inverted as well, so the behaviour was correct, but
the function name wrong
Fix #18: cast null pointer as disconnect signal parameter