python 3 issue in io.py

[jmmshn]

The line in io.py causes an AttributeError (sometimes)

 lastchar = m_file.read(1).decode("utf-8")

Is not compatible in python 3 if the input file is not opened as a byte stream.

I get this exception when certain fireworks are restarted. But I haven't spent the time to track down the exact cause.

The line above breaks in the following way

AttributeError                            Traceback (most recent call last)
<ipython-input-10-aa14052e5034> in <module>
      1 with open('text.file', 'r') as f:
----> 2     f.read(1).decode("utf-8")

AttributeError: 'str' object has no attribute 'decode'

but if you change it to f.read(1).decode("utf-8") the code works.

If you think it's appropriate, I can modify the code to make it handle both 'r' and 'rb' read cases

[shyuep]

Sure, pls make the change. Thanks.