Replace ukbhit by kbd_enter_pressed, not requiring tcgetattr:

Note that it behaves differently now
* it looks for Enter key only, not any key
* it "eats" the input, no need for (void)getchar() after it
* it works the same no matter the value of ICANON
* the mingw version has been adapted to act the similarly

This should fix its usage on Android where tcgetattr always returns -1

client/scripts/lf_bulk.lua

@@ -186,7 +186,7 @@ local function main(args)
     for cardnum = baseid, endid do
         local card = cardHex(cardnum, facility)
         print('Press enter to program card '..cardnum..':'..facility..' (hex: '..card..')')
-        --This would be better with 'press any key', but we'll take what we can get.
+        --This would be better with 'press Enter', but we'll take what we can get.
         io.read()
         core.console( ('lf hid clone %s'):format(card) )
     end