Comment in MCP370xx __init__ inconsistent with code

[RobertBaruch]

• Platform/operating system (i.e. Raspberry Pi with Raspbian operating system,
  Windows 32-bit, Windows 64-bit, Mac OSX 64-bit, etc.): RasPi 3, Raspbian Jessie
• Python version (run python -version or python3 -version): 3.4.2
• Error message you are receiving, including any Python exception traces: N/A
• List the steps to reproduce the problem below (if possible attach code or commands
  to run): N/A

The __init__ code comment in MCP370xx.py says it is setting the iodir register for all inputs. However, all inputs would be [0xFF]*self.gpio_bytes. The code sets iodir register for all outputs.