Fixed applet filename issue + expanded MCU definitions to support more chip IDs

Windows users:

Download mdloader_windows.exe and applet-mdflash.bin and put them in the same folder.

Linux users:

Download mdloader_linux and applet-mdflash.bin and put them in the same folder.
chmod u+x mdloader_linux to make it executable.

Mac users:

Download mdloader_mac and applet-mdflash.bin and put them in the same folder. If downloading with Safari, mdloader_mac with have a .dms extension appended to it. This is fine.

chmod u+x mdloader_mac to make it executable. (chmod u+x mdloader_mac.dms if downloaded from Safari)