User account page updates
* Code copied from core of checkout page, account form generation now uses same logic as checkout page
* Deprecated functions updated to include user log specific filters, as visitor filters perform the same function WPeC wide
* Addresses issue #1174, merge PR #1173 before this PR is merged

also...
Checks for checkout page container present prior to scrolling window
Check for having valid zip code now looks to see if we need a zip code.  Valid zip code is determined if we need a zip code and the customers shipping postal code is not blank.