Merge pull request #1 from xcore/master

getting up to date with xcore
updated CHANGELOG
updated CHANGELOG
Merge pull request #2 from xcore/master

Getting up to date with xcore
Corrected failure return values (module_i2c_simple returns 1 on success)
Updated comments to reflect that the nbytes parameter is now respected
Improved clarity of write function comment
Merge pull request #41 from xsamc/nack_return_fix

NACK return fix