ecomm fixes: use price instead of cost_price. Fixing taxon locator to be more flexible.

Also added :throws_exception => false to the MC API call
Although this doesn't work on the current MC gem master
mailchimp/mailchimp-gem/pull/30 adds this functionality in
Fixing ecomm date formatting bug

V2.0 of the docs states that order_date must in the format 2012-12-30
Cleaning up Gemfile to be a bit cleaner based on gemspec definition
Fixing failing specs
Merge pull request #27 from iloveitaly/ecomm-add-fix

Ecomm Add Fixes
Skips merge vars that are not defined on the model
Dont call changed? method unless is exists
Removed categorie info, because method used for finding categories is not generic
Adds memoization to api service objects
Replaces uses of `mock` with `double`
Adds call to reset config before each test
Fixes deprecation warnings related to #should_receive
Adds rake task for syncing merge vars with mail chimp
Fixes spelling
Revert "Removed categorie info, because method used for finding categories is not generic"

This reverts commit da57817235673943bfc21bba55a6b3a3635ae584.
Adds check for nil taxon, sends as "Uncategorized"
Updates order api to use Order#item_total instead of #total
Adds List#info for returning member info based on id
Symbolizes keys returned from List#info
Updates List#info to return empty hash on error