-Fixed an issue preventing Pictoric from starting automatically upon login
-Fixed numerous directory related issues. Pictoric should display error messages when nonexistent or empty directories are chosen
-Fixed various crashes and instances of high CPU usage due to Pictoric continuously searching directories with no image files
-Now allows image files with not all lowercase extensions (i.e .PNG or .JPEG)
-Now prevents multiple instances of Pictoric from running simultaneously that may have been causing crashes