TODO list for Perl module Handel

    - write tests for order/checkout framework
    - add sql schema and conversions using SQL::Translator
    - add ConfigReader config for plugins namespace
    - write basic plugins
    - write TT2 plugins for order/checkout framework
    - write AxKit taglibs for order/checkout framework
    - enhance demo sites to use full feature set
    - slim Cart taglib code to remove repeated code blocks left for clarity
    - find translation volunteer other than Google translate
    - clean up cart test variable names
    - add additional cart restore w/filter tests for multiple saved carts
    - devise method for overriding constraints