Checkout Form Class Fix and Enhancement
Started using checkout form class functions in place of a couple of queries that were repeated in various places adounrd the code and noticed a couple of things.

* The data from the database that is stored in the class static can be retrieved with a parameter excluding heading fields but if a later call tries to retrive the values with heading fields the heading fields wouldn't get returned.  Changed the query to always retrieve the heading fields. Changed the retrival function to filter out heading fields if the caller asked for them to be filtered.

* Added a class function to return the count of fields

* Noticed that the version number was set to 3.9, since we are using the functions in 3.8.14 changed the version number in the header
Changed file back to upstream master to remove unneeded changes
The updates
Was about to do a tiny bit of work in the cart calss part of the cart.class.php and noticed that the file would benefit from a little cleanup before I made changes.

* This commit deosn't have any logic changes other than the deprecated functions noted here.
* the template functions were moved to a distinct file.
* The cart class is now the only thing in the cart.class.php file.
The google checkout functions have been deprecated. Note that one google checkout function is a part of the
cart class.  That function has been deprecated in place.
To preserve backwards compatibility changed ordr of includes to give same result as prior to 3.8.14
Added a wpsc doing it wrong message if a direct include of cart.class.php is detected
Removed google checkout related call
Removed call to wpsc_google_checkout.

The wpsc_google_checkout function is still intact, but in the deprecated functions file.  It will display a warning when someone who has upgrades has a copy of the widget theme file in thier theme.
Merge pull request #991 from JeffPyeBrook/cart-class-to-its-own-file

Cart Class File Cleanup and Function Deprecation
Changed version number to 3.8.10
Added public to constructor
Merge pull request #990 from JeffPyeBrook/checkout-form-test-fixes

Checkout Form Class Fix and Enhancement