Bugfix user_errors causing failed install
Merge pull request #97 from nhorstmeier/InstallationBugfix

Bugfix user_errors causing failed install
ProductPage - make Code unique

Fixes #84

Added unique index on Code. Added AjaxUniqueTextField for Code.

Updated depreciated GridField component call on GridFieldBulkUpload.

Changed Code from Text to Varchar(100)

Signed-off-by: Jason Irish <jirish@dynamicdoes.com>