Add EPV2in13v2 support

[mil]

There's a new version of the EPD2in13; see: https://www.waveshare.com/wiki/2.13inch_e-Paper_HAT#Versions

I've added over the lut_full_update/lut_partial_update from their new sample code; and can report with this full refresh works, e.g. using --nopartial.

For some reason partial update doesn't quite work.

[joukos]

Thanks for the contribution! I don't have time (or hardware) to look at this right now, but quickly glancing the updated demo code, the initialization looks a bit different and it spits bytes at the device in init() that aren't included in the old code, such as:

...
            self.send_command(0x74) #set analog block control
            self.send_data(0x54)
            self.send_command(0x7E) #set digital block control
            self.send_data(0x3B)
...

So your best bet might be to override the whole init method in the driver class and make it do the same stuff as the demo code, perhaps then it will work.

I'll merge this anyway since it works with full refresh.