STM8 support in vsprog

Information:
    Vsprog can support STM8 in SWIM interface.
    Auto-detect feature is NOT supported on STM8
    Supported target area: flash('f'), fuse('u'). Note, for STM8, lock(ROP) is defined in fuse. MTU of STM8A is also supported.

Vsprog options:
    -sstm8, refer to -s option.
    -c, refer to -c option.
    -m, refer to -m option. Supported modes:
        s: SWIM mode, default
    -t, refer to -t option. Target area defined by -t option is fuse.