kdesrc-build setup for kdepim

[Alex Merry]

The recent splitting of kdepimlibs has caused a clean run of 
kdesrc-build to fail on lots of pim modules. This seems to be a 
combination of kde-build-metadata not recording the dependencies 
properly for a lot of things, and "playground/pim" in the kdepim 
kdesrc-build include file being far too general (eg: akonadi-vkontakte 
is kdelibs4-based, not kf5-based).

I started trying to fix it, but got a bit overwhelmed. It would be 
easier for someone / some people with domain knowledge to do it, I 
think, hence me emailing the kde-pim list.

Also, I'd like to point out that it is incredibly confusing when 
non-Frameworks libraries claim to be in Frameworks (by prefixing their 
CMake module names with "KF5", like KF5Async). When I see 
find_package(KF5Foo) in a CMakeLists.txt file, I expect KF5Foo to 
actually be a KDE Framework. Could we move away from calling things KF5* 
until they are actually in frameworks (ie: in the frameworks/ directory 
on the KDE servers, and expected to go into a Frameworks release soon)? 
Apart from anything else, moving previously-released stuff into the KF5 
namespace when they join Frameworks will probably help packagers.

Alex