Merge pull request #14 from mc12345678/master

Updated to work with ZC 1.5.3
Updated version to 4.0.24

Updated version after pull request from mc12345678. This version
incorporates fixes to be compatible with zencart 1.53
Update: Fixed Error in attributes import

Variable name was missing $, which caused mysqli to throw an error. Also
made a change to how $products_options_values_sort_order was
incremented. Will suggest making this an config variable for "increment
by"
Attributes sort order fix

minor bug in how the next index number was being calculated
Merge pull request #2 from chaddro/master

Update Local copy to remote copy