Add tests for declaration lookup in QtHelp plugin

Shows some ill behavior when looking up help for custom operator
functions (e.g. some customer 'operator<' overload). Not that easy to
fix, though. Just adding the tests add some QEXPECT_FAIL marker instead.
Minor: Cleanup
This should have been 'Abort'...
Fix this in case Qt documentation is missing
Add batch edit mode to the Defines and Includes GUI

Now it's possible to modify many include directories and defined
macros at the same time.

REVIEW: 118191
Show label with warning when trying to add an unexisting path.
Make the cmake parser understand the CONFIG argumente in find_package

Fixes the loading of some projects that use this flag
Sometimes we get tempty dependencies, just skip them
Process find_package as many times as possible

We used to only do it once, but having different components changes things
because a find_package call can find a component and another one, a
different component. So just obey.
Support CMAKE_INCLUDE_CURRENT_DIR_IN_INTERFACE

If it is defined, add the target's dir to the interface
Implement visibility for target_include_directories calls
Rename plugintest to definesandincludestest

Back then I didn't know that the test name will be visible when
executing the "make test" command.