TODO update
adopting to changes in OpenLibrary
cmake: removing qt5_use_modules()
core: removing TaskExecutorConstructor, TaskExecutor is no singleton anymore
database: taking TaskExecutor from main
gui: passing ITaskExecutor down thru hierarchy
core: link fix
gui: New, empty implementation of ImagesTreeView
gui: ImagesTreeView: starting development
configuration: extending interface with convenience findEntry() function; new basic key introduced
database tools: passing configuration to PhotosAnalyzer
fixing potential problems with struct/class mismatch
PhotoInfoUpdater: taking thumbnail width from config
passing configuration to ImagesTreeView
configuration: convenience findEntry() function added
gui: ImagesTreeView: implementing visualRect() with necessary stuff
gui: ImagesTreeView: code refactor.
gui: ImagesTreeView: preparations for paintEvent
code refactor
gui: ImagesTreeView: paintEvent continued