Added a button and the functionality to clear all downloaded images (all images within subfolders at picsPath/downloadedPics) under Settings.
Added notification messages informing users of the success or failure of clearing downloaded images.
Moved the button from the paths section to be below the "Download high-quality card pictures" checkbox. Button now reads "Reset/Clear Downloaded Pictures". Removed "Path to"s from card/token database, hand/stack/table/player info background, and card back labels.
Merge pull request #265 from pliu037/clear-downloaded-pics

Clear downloaded images from settings
Merge remote-tracking branch 'upstream/master' into valgrind