Py3 compat: replace use of "unicode" (pwr/Solaar#32)

Generating "an unknown notification" type bailed out because of an unknown
feature type None. Since `isinstance(other, str)` is False for None, the script
will raise an exception on `isinstance(other, unicode)`.

There is no differentiation between `str` and `bytes` in Python 2, therefore
add another condition to `NamedInt.__eq__` to catch unknown types (like
`bytes`).