[Nut-upsuser] apcsmart dev branch

[Michal Soltys]

Hi,

The devel branch has some long standing updates implemented - mostly a 
result from past bug/issue reports. Among those:

- selectable normal / canonical mode (useful in windows and perhaps with 
some problematic usb/rs cards)
- some compat entries
- certain (old) class of psus returning something else through 'b' 
treated as a whole set
- can handle mutlivalue entries (e.g. 'T')

I'm still a bit reluctant to merge it without a bit wider exposure, so 
if anyone has a possiblity to test it with some apc units - any feedback 
would be most welcome.