Merge pull request #3 from ionux/master

Added new HTTP header for version tracking and updated README
Merge pull request #4 from ionux/master

Updated to work with Prestashop 1.6 and better backward compat. support
Merge pull request #6 from ionux/master

Added backup JSON en/decoding functions
Merge pull request #7 from ionux/master

Fix to user server error handling
Added CHANGELOG, added LICENSE, added license text to all files
Added CHANGELOG, added LICENSE, added license text to all files
Merge pull request #9 from cstevens88/master

Added CHANGELOG, added LICENSE, added license text to all files
Resolved missing order issue