change IOError handling
change IOError handling

The API now raises an IOError with an errno and a strerror property.
This can be useful to handle different IOErrors. This is especially
useful for the I2C status code.

Signed-off-by: Michael Walle <80e54fab1167aac9a5a5dfc5e0e0a3e5102ca3bd@kontron.com>

kontron/python-aardvark,hthiery/python-aardvark