okularplugin target from mobile/components suffers from the same problem as okularpart in https://git.reviewboard.kde.org/r/125741/
But the cause is a bit different now. okularplugin uses settings.cpp generated by KConfig and its header declares Settings class with OKULARCORE_EXPORT. For okularplugin target this macro gets expanded to __declspec(dllimport) and it makes linker to look for Settings class symbols in okularcore.
Fix this by tricking VS that we are building okularcore target.
REVIEW: 125742
when pinching, just scale the item, this scales the texture
with the GPU, avoiding costrly redraws.
redraw at the correct size only when the gesture ends