releaseme now relying on kdoctools for documentation installation

[Harald Sitter]

Hola!

As per [1] the release management suite releaseme creates tarballs
which rely on kdoctools to process a directory with docbooks inside.
Previously releaseme manually constructed CMakeLists suitable for the
documentation lineup at hand. This required an excessive amount of
fairly poorly engineered code though, so this change should increase
the overall reliability of documentation installation.

Unfortunately, this also comes with a slight downside as previously
releaseme would try very hard to retain logic in the english
documentation (e.g. if branching as seen at [2]) and carry it into
translations. As kdoctools doesn't do this I'd suggest that you review
your documentation cmakelists and drop conditional install logic to
ensure your documentation installation will be consistent between en
and l10ns.

As an additional step you'll want to make sure that your doc/
directory is actually being installed. Previously releaseme would
force its installability through the cmakelists construction, which no
longer exists, so your source trees will no longer get a helping hand
with this.
To check simply make sure your git clone installs
'$prefix/share/doc/HTML/en/...'. If it doesn't your cmake code is
deficient.

[1] https://commits.kde.org/releaseme/d701767a34fc38b24fb5d4379338fc1420f2ef54
[2] https://cgit.kde.org/plasma-workspace.git/tree/doc/CMakeLists.txt?id=d9adb0b3fccf4e2c367619a13923b0cea08625e8

HS