Previously it was not clear whether the units in tdehwlib are
in Wh and W or Ah and A. Now the units are always Ah and A.
Because power consumption is usually given in W, the value is
converted from A to W. If it is less than 100 W, it is
displayed as a decimal number.
This is related to issue TDE/tdelibs#68.
Signed-off-by: Slávek Banko <email@example.com>