I've added 'optimize' option (by default true). If it options is set
then sources will be checked if they are required (with dependencies if
any). And if they are not required they will be dropped by using common
mechanism.
Please note that if this option enabled the following features (at the
moment) will be unavailable:
* key request from context menu (from configuration interface it still works)
* notifications event if sources on which notification is not connected
I suppose this commit will increase performance in about 4-5 times.
I suppose the better way is to move weather adaptor to another open
weather engine despite the fact that OWM has provided me a special FOSS
permissions. I've changed weather provider to Yahoo! Weather because
there is no good way to provide my own API key to end-users except for
being compiled to the source code.
In other hand this solution leads to the fact that humidity and
atmosphere pressure is not available for forecast more. And moreover
pressure units has been changed for current weather.
+ fix possible memory leak in dataengine aggregator
+ add "special thanks" group to acknoledgment tab
This fact caused by the qt signal-slot implementation. Even if slots
code is going into parallel they will be called in the main app thread.
And also it is used inside KF5 dataengine implementation, so I'm affraid
that it could not be optimized w\o backend rewriting
* create QTimer object in AWDataEngineAggregator class, emit signal to
this timer because timers could not be started in the separate thread
* increase limit x2 with leaving the thread pool size as was
