WPSC_Meta Class Implementation

WPSC_Meta class implements meta value access with efficient caching for
small and large values.  The class provides methods for accessing meta
data items individually and as collections.
Fix: prevent preg_match() warnings from occurring if the products page is draft.

Should fix Issue #441.

If the products page doesn't exist (or is a draft), revert to using /product/xyz/ permalinks for products.
Custom Object Meta Support

Implements custom object meta support using the WordPress common meta
infrastructure.  Includes access functions for known WPEC object types.
Access functions mirror the WordPress 'post' meta functions.  Includes
conversion routine to move data from wpsc_meta to new architecture.
Includes functionality to allow developers to generate meta support for
new custom objects.

As discussed in #400
Changes based on review feedback

Fixed spaces, removed debug cruft, removed tick marks from SQL to be
sent to dbDelta
Merge branch 'Custom-Object-Meta' into branch-3.8.11.1
Custom Object Meta Support

Implements custom object meta support using the WordPress common meta
infrastructure.  Includes access functions for known WPEC object types.
Access functions mirror the WordPress 'post' meta functions.  Includes
conversion routine to move data from wpsc_meta to new architecture.
Includes functionality to allow developers to generate meta support for
new custom objects.

As discussed in #400
Changes based on review feedback

Fixed spaces, removed debug cruft, removed tick marks from SQL to be
sent to dbDelta
Merge branch 'branch-3.8.11.1' of https://github.com/JeffSparkleGear/WP-e-Commerce into branch-3.8.11.1
added project to .ignore
All function now prefixed with 'wpsc_
Added prototype function for iterating meta by timetamp
Renamed file to be consistant with the wpsc support files for each of
the wpsc core custom meta types
Cleaned up code to coding standards using CodeSniffer reports
core meta types ready for pull request review

core meta types cart_item and visitor( was customer ) ready for pull
request review
Updated version information, removed debug code
Deleted .gitignore
Center fancy notification window
config files
config
Post testing bug fix