DirMaster v3.1.2/Style

Issues reported by users that were addressed in v3.1.2:

• workaround for high dpi issues reported by users on Windows 10 (Windows 7/8 still affected, known issue)
• drag/drop from a disk image to the file system handles "broken" files more gracefully.
• corrects issue moving .cvt files between disk images
• page up/down works in the petscii column on the sector editor
• tweaks: hexedit font toggling, BAM view, Explorer preview font size