Drop CardInfo’s own pixmap caches; use QPixmapCache instead.
Use QPixmap references instead of pointers.
Being stored in QPixmapCache, all card images are now subjected to
QPixmapCache’s size limit
cardframe is now a stacked widget that prefers to show the card picture
only so that the screen can be more space efficient and the card pixel
map can be displayed as a larger size. however if the card pixel map
can not be loaded for some reason, the cardframe class will automatically
switch to the text version of the card.
a menu item was added under the database menu to allow for users to
prefer card text only.
