The last few weeks I've done quite a bit of QCA cleanup.
Bit of a summary:
* Moved to KDE's gitlab and enable clazy and clang-tidy continuous integration checks
* Fixed lots of crashes when copying some of the classes, it's not a normal use case, but it's supported by the API so make it work :)
* Fixed lots of crashes because we were assuming some of the backend libraries had more features than they actually do (e.g. we thought botan would support always support a given crypto algorithm, but some versions don't, now we check if the algorithm it's supported before saying it is)
* Made all the tests succeed :)
* Dropped Qt4 support
* Use override, nullptr (Laurent), various of the "sanity" QT_* defines, etc.
* botan backend now requires botan2
* Fixed most of the compile warnings
What I probably also did is maybe break the OSX and Windows builds, so if you're using QCA there you should start testing it and propose Merge Requests.
Note: My original idea was to actually kill QCA because i started looking at it and lot of the code looked a bit fishy, and no one wants crypto fishy code, but then i realized we use it in too many places in KDE and i'd rather have "fishy crypto code" in one place than in lots of different places, at least this way it's easier to eventually fix it.