Customer meta and checkout

Continuing on from the several recent commits that have already been merged into master related to checkout, customer meta, cart cleanup and javascript handling it's time to pull them all together.

There related changes are all in PRs and can be merged and used independently. Prior to merging this PR, these specific PRs should be merged.  It's likely that if they are not merged prior to addressing this PR auto merge will not work.

#985 Eliminate the dynamic creation and queuing of dynamic js script
#986 Gracefully Deprecate "checkout_details" customer meta
#989 Country region currency API
#994 Coding standards update
#996 wp-e-commerce.js changes should force browser and cache reload
#998 Updates to protect cart template API and WPEC from improper usage

Going forward and through testing this PR will have the remaining fixes, with the merged PRs above.