The weather ion dataengines used to take care for weather observation
reports whether it was day or night at the given location ATM, and to choose
icons with the sun or the moon respectively.
For that they made use of the time dataengine which provides calculated data
for solar-system related things. Though that calculation services was
queried with a sync call, which is no longer existing in Plasma5 age.
While it might have been possible to switch to async querying of the time
dataengine, the needed additional bookkeeping of the new states would add
quite some complexity. Where the straight call into the respective
calculation code is both more simple and also avoids additional default
calculation done by the time dataengine.
Because the "solarsystem" code in the time dataengine is not separatly
available, this patch copies the code files over and adapts them as
minimally as needed.
As the solarsystem code is also GPL, mixing it as private API into the
LGPL weather_ion library seems not recommended.
So a separate private shared library is created installed and used/linked
from the weather ion data engines.